Re: [expert] Using Postfix to send mail.
On Wed, 2003-07-23 at 14:00, Joerg Mertin wrote: Thx Franki, I'll give it a try. Right now - on all the Mails I have seen tagged as Spam, and I also asked all users to check the Spam-Mails they have received - It didn't happen so far - that a non-Spam Mail was tagged as Spam. Rather the other way around - that Spam-Mail got undetected through the Spam-Filter (I don't know yet of an Easy way to tell Spamassassin that this is a Spam ? (Got version 2.55 :)... Specially some Mails are created where all Tag-Words are disguised - as we use to disguise E-Mails... [EMAIL PROTECTED]@ or only a Gif-File containing the entire Message. Has anyone of you automatised Spamassassin - to manually tag undetected Mails ? I mean - having a alias tagspam pointing to user filter filter - that the spamd/spamc are running on - you bounce a Mail to - and the script knows - that everything coming through here _is_ spam - so the bayes part can learn something. Anyone of you folks did that already - or will I have to do it myself ;) So - I am quite confident that losses would be minimal if I save them on a Local Directory. Cheers Joerg Joerg, One thing you could do.. it could be deadly if you get a lot of e-mail via Outhook excess. Filter for and drop all html e-mail. God knows it can be an extreme action, but in my case the amount of p0rn spam and the type of spam was way too much for me to stomach. So it all goes into the bit bucket. James On Wednesday 23 July 2003 21:15, Frankie wrote: ok, well when i get some time, I will knock up a howtoo.. (and put it on the twiki) but in answer to one of Joerg's question go to the postfix site and grab the latest snapshot. there is some documentation on the proxy methods. (also the postfix mailing list archives.) rgds Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James Sparenberg Sent: Thursday, 24 July 2003 1:07 AM To: Expert List Subject: Re: [expert] Using Postfix to send mail. On Wed, 2003-07-23 at 04:59, Joerg Mertin wrote: Hia there, so - actually - the new possibility with the Proxy sounds quite interesting, and are what I was looking for a long time now. Does anyone has some hints as what I'd need for it (which version of Postfix would be required), and some examples - on how to configure all that ? Of course - a detailed HOWTO would be best :) And of course ... post it in the community TWiki *grin* Thx for all your Input folks :) On Wednesday 23 July 2003 12:46, Frankie wrote: [...lots of intersting stuff deleted...] Joerg Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On 23 Jul 2003 23:08:07 -0700 James Sparenberg [EMAIL PROTECTED] wrote: One thing you could do.. it could be deadly if you get a lot of e-mail via Outhook excess. Filter for and drop all html e-mail. God knows it can be an extreme action, but in my case the amount of p0rn spam and the type of spam was way too much for me to stomach. So it all goes into the bit bucket. Yup... pretty extreme! :^) Using nothing but postfix rules, I still manage to keep my spam down to one (1) that sneaks through per day on average -- though virtually 100% of those come from mailers matching this regexp: /.*dsl.*/ so I'm thinking to blocking all those... Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
RE: [expert] Using Postfix to send mail.
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James Sparenberg I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. It is a little bit of both. Some dynamic IP addresses will be blocked because they are dynamic and some don't. The forward and reverse lookup is a complete different thing. every ip address and domain in e-mail traffic must be forward and reverse resolvable. sometimes it works without, but most of the time it don't. Stef The other thing I've run into..(Mainly with gnu list serv lists.) is that apparently the RFC requires that [EMAIL PROTECTED] exist. If it doesn't they will refuse all e-mail, Even if you have reverse DNS etc. Great idea now I'm guaranteed to have an e-mail address spammers can send to. It is not only this address. There are some more. If you dont hav all these addresses enabled you can find your server on a list of rfc-ignorant.org. There are som mail server outside which don't accept mails from servers listed in rfc-ignorant.org. But on the other hand, if you have problems with one Mailserver how can you inform the server administrator if the postmaster mailbox does not exists? BTW, in the last four years, I haven't got any spam on the postmaster mailbox. Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James # Yeah, worst thing I did was add wildcard address's to the virtual file.. @mydomain.com franki between that and my postmaster admin accounts amount to about 30% or more of the 50-100 spam I get a day... If I didn't have spamassassin running on the server, I'd have been driven up the wall by now. regards Franki Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 07:46 schrieb Frankie: -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James ... Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James # Yeah, worst thing I did was add wildcard address's to the virtual file.. @mydomain.com franki between that and my postmaster admin accounts amount to about 30% or more of the 50-100 spam I get a day... If I didn't have spamassassin running on the server, I'd have been driven up the wall by now. The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. regards Franki Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 08:41 schrieb Martin Fahrendorf: Am Mittwoch, 23. Juli 2003 07:46 schrieb Frankie: -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James ... Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James # Yeah, worst thing I did was add wildcard address's to the virtual file.. @mydomain.com franki between that and my postmaster admin accounts amount to about 30% or more of the 50-100 spam I get a day... If I didn't have spamassassin running on the server, I'd have been driven up the wall by now. The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. Oh, the main problem is not amavis but spamassassin (but we run spamassassin by amavisd-new). Martin regards Franki Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
RE: [expert] Using Postfix to send mail.
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Martin Fahrendorf Am Mittwoch, 23. Juli 2003 08:41 schrieb Martin Fahrendorf: Am Mittwoch, 23. Juli 2003 07:46 schrieb Frankie: -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James ... Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James # Yeah, worst thing I did was add wildcard address's to the virtual file.. @mydomain.com franki between that and my postmaster admin accounts amount to about 30% or more of the 50-100 spam I get a day... If I didn't have spamassassin running on the server, I'd have been driven up the wall by now. The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. Oh, the main problem is not amavis but spamassassin (but we run spamassassin by amavisd-new). Martin Yeah, but using the new postfix proxy methods should fix that nicely.. its not really any great use overall, but its a great feeling to reject spam in realtime rather then filter it.. I have read that people are already using it with amavis-new. An ego trip even. :-) rgds Franki Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Hi Martin, On Wednesday 23 July 2003 08:47, Martin Fahrendorf wrote: [...] The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. Oh, the main problem is not amavis but spamassassin (but we run spamassassin by amavisd-new). I know that I could reject spam directly through spamassassin - however - I do use the combaination: postfix, cyrus-imapd, spamassassin, anomyser - and have not yet found a decent script that rejects Spam when it comes in. Would be nice - as I have about 5 Persons (Friends) getting Mails through my server - and we're getting in about 50 Spams/Day ... Any hint on that, LInk I could read some stuff etc. The example that came with anomy/spamassassin-scripts are not all that satisfaying IMHO. Thx for a hint Joerg -- Do not meddle in the affairs of troff, for it is subtle and quick to anger. | Joerg Mertin : [EMAIL PROTECTED](Home)| | in Neuchâtel/Schweiz : [EMAIL PROTECTED] (Alt1)| | Stardust's LiNUX System : [EMAIL PROTECTED](Alt2)| | Web: http://www.solsys.org: Voice Fax: +41(0)32 / 725 52 54 | PGP Fingerprint: AF0F FB75 997B 025F 4538 5AD6 9888 5D97 170B 8B7A Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 09:55 schrieb Joerg Mertin: Hi Martin, On Wednesday 23 July 2003 08:47, Martin Fahrendorf wrote: [...] The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. Oh, the main problem is not amavis but spamassassin (but we run spamassassin by amavisd-new). I know that I could reject spam directly through spamassassin - however - I do use the combaination: postfix, cyrus-imapd, spamassassin, anomyser - and have not yet found a decent script that rejects Spam when it comes in. Would be nice - as I have about 5 Persons (Friends) getting Mails through my server - and we're getting in about 50 Spams/Day ... Any hint on that, LInk I could read some stuff etc. The example that came with anomy/spamassassin-scripts are not all that satisfaying IMHO. Thx for a hint Joerg As Frankie said, the new postfix (the snapshot releases do it as well) kan handle the rejection via the proxy method. the first postfix instance take the mail but does not tell the sending server that it accepts it. Only if some proxy program like spamassassin accepts it, postfix accepts it too and the delivery contains. But if spamassassin says no, the mail will be rejected. There is no way to tell postfix reject spam mail with spamassassin in the current version. But afaik the snapshot versions of postfix are relative stable. Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
Re: [expert] Using Postfix to send mail.
Hi Martin, thx for the hint. I might give it a try. However - what buzzes me here is that if you use the proxy method to identify spam - you have to get the spam anyway through it - don't you ? So - the spam will use your bandwidth to get analyzed by the proxy application - and the proxy application then returns a Spam-Detected message which will be interpreted by the postfix process and which will make that one reject the message definitly. IMHO - the only difference is that the remote side will get a reject message if I understood correctly the process. Please correct me if I'm wrong. Do you think this reject message will inhibit spammers to send you more mail ? NOTE - the actual spamassassin/postfix/anomy method enables you to actually get the Mail in, spamassassin checks it through spamc/spamd - and if it's beeing detected a SPAM - you can tell the delivery script to delete it or move it to a local-file for laer analysis ... Cheers Joerg On Wednesday 23 July 2003 10:19, Martin Fahrendorf wrote: Am Mittwoch, 23. Juli 2003 09:55 schrieb Joerg Mertin: Hi Martin, On Wednesday 23 July 2003 08:47, Martin Fahrendorf wrote: [...] The main problem with amavis and postfix is a missing feature in the current postfix version. You can not reject spam mails. So you lose ane defence line in your battle against spam. Oh, the main problem is not amavis but spamassassin (but we run spamassassin by amavisd-new). I know that I could reject spam directly through spamassassin - however - I do use the combaination: postfix, cyrus-imapd, spamassassin, anomyser - and have not yet found a decent script that rejects Spam when it comes in. Would be nice - as I have about 5 Persons (Friends) getting Mails through my server - and we're getting in about 50 Spams/Day ... Any hint on that, LInk I could read some stuff etc. The example that came with anomy/spamassassin-scripts are not all that satisfaying IMHO. Thx for a hint Joerg As Frankie said, the new postfix (the snapshot releases do it as well) kan handle the rejection via the proxy method. the first postfix instance take the mail but does not tell the sending server that it accepts it. Only if some proxy program like spamassassin accepts it, postfix accepts it too and the delivery contains. But if spamassassin says no, the mail will be rejected. There is no way to tell postfix reject spam mail with spamassassin in the current version. But afaik the snapshot versions of postfix are relative stable. Martin -- No directory. | Joerg Mertin : [EMAIL PROTECTED](Home)| | in Neuchâtel/Schweiz : [EMAIL PROTECTED] (Alt1)| | Stardust's LiNUX System : [EMAIL PROTECTED](Alt2)| | Web: http://www.solsys.org: Voice Fax: +41(0)32 / 725 52 54 | PGP Fingerprint: AF0F FB75 997B 025F 4538 5AD6 9888 5D97 170B 8B7A Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 10:49 schrieb Joerg Mertin: Hi Martin, thx for the hint. I might give it a try. However - what buzzes me here is that if you use the proxy method to identify spam - you have to get the spam anyway through it - don't you ? So - the spam will use your bandwidth to get analyzed by the proxy application - and the proxy application then returns a Spam-Detected message which will be interpreted by the postfix process and which will make that one reject the message definitly. IMHO - the only difference is that the remote side will get a reject message if I understood correctly the process. Please correct me if I'm wrong. Jepp, that's right. Do you think this reject message will inhibit spammers to send you more mail ? Hm, that is wild guessing. I think spamers dont want to waste bandwith, they want to get their mails read. If you silently delete the spam the spamer don't know if their mails get read or not. So they assume thei can send their mails again. If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. Do they send spam again? Yes, I fear they see it as a kind of sport to get their spam trough. But doing nothing is no sollution. NOTE - the actual spamassassin/postfix/anomy method enables you to actually get the Mail in, spamassassin checks it through spamc/spamd - and if it's beeing detected a SPAM - you can tell the delivery script to delete it or move it to a local-file for laer analysis ... Cheers Joerg Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
RE: [expert] Using Postfix to send mail.
Well, at the high end of the spam game they do tests to see if an address is valid or not.. such things as image links in email that are actually links to a server side script at their end that is passed an id matching the email address that that particular message was addressed to. Also some record if the message was bounced or not, and this is where bouncing the spam back can be handy.. because the email address will not be validated as accepted and therefore it might be removed from the spammers Database. Since many spammers use fake yahoo address's to send a ton of mail out in a short time, overloadign their accounts with bounced messages is a good thing too. It will have a likewise beneficial effect on ISP's like the russian spam servers, whereby a huge stream of bounce messages uses up some of the servers bandwidth, and costs them money.. so they would be more inclined to do something about it. A last benefit is the ego... its great to feel that you are being active rather then reactive with regards to spam.. filtering just doesnt' feel as good as rejecting spam... :-) Right now this sort of thing is the best method we have for reducing spam that is unintrusive (unlike challenge response methods). They guys that come up with stuff like postfix proxy are legends (and WV, the creator and maintainer of postfix (and tcp wrappers) is a surprisingly nice guy, (unlike D Beirnstein (qmail), who is an egocentrical ellitist)) both are undoubtably brilliant though. regards Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Martin Fahrendorf Sent: Wednesday, 23 July 2003 5:55 PM To: [EMAIL PROTECTED] Subject: Re: [expert] Using Postfix to send mail. Am Mittwoch, 23. Juli 2003 10:49 schrieb Joerg Mertin: Hi Martin, thx for the hint. I might give it a try. However - what buzzes me here is that if you use the proxy method to identify spam - you have to get the spam anyway through it - don't you ? So - the spam will use your bandwidth to get analyzed by the proxy application - and the proxy application then returns a Spam-Detected message which will be interpreted by the postfix process and which will make that one reject the message definitly. IMHO - the only difference is that the remote side will get a reject message if I understood correctly the process. Please correct me if I'm wrong. Jepp, that's right. Do you think this reject message will inhibit spammers to send you more mail ? Hm, that is wild guessing. I think spamers dont want to waste bandwith, they want to get their mails read. If you silently delete the spam the spamer don't know if their mails get read or not. So they assume thei can send their mails again. If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. Do they send spam again? Yes, I fear they see it as a kind of sport to get their spam trough. But doing nothing is no sollution. NOTE - the actual spamassassin/postfix/anomy method enables you to actually get the Mail in, spamassassin checks it through spamc/spamd - and if it's beeing detected a SPAM - you can tell the delivery script to delete it or move it to a local-file for laer analysis ... Cheers Joerg Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Hia there, so - actually - the new possibility with the Proxy sounds quite interesting, and are what I was looking for a long time now. Does anyone has some hints as what I'd need for it (which version of Postfix would be required), and some examples - on how to configure all that ? Of course - a detailed HOWTO would be best :) Thx for all your Input folks :) On Wednesday 23 July 2003 12:46, Frankie wrote: [...lots of intersting stuff deleted...] Joerg -- No line available at 300 baud. | Joerg Mertin : [EMAIL PROTECTED](Home)| | in Neuchâtel/Schweiz : [EMAIL PROTECTED] (Alt1)| | Stardust's LiNUX System : [EMAIL PROTECTED](Alt2)| | Web: http://www.solsys.org: Voice Fax: +41(0)32 / 725 52 54 | PGP Fingerprint: AF0F FB75 997B 025F 4538 5AD6 9888 5D97 170B 8B7A Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On Wed, 2003-07-23 at 04:59, Joerg Mertin wrote: Hia there, so - actually - the new possibility with the Proxy sounds quite interesting, and are what I was looking for a long time now. Does anyone has some hints as what I'd need for it (which version of Postfix would be required), and some examples - on how to configure all that ? Of course - a detailed HOWTO would be best :) And of course ... post it in the community TWiki *grin* Thx for all your Input folks :) On Wednesday 23 July 2003 12:46, Frankie wrote: [...lots of intersting stuff deleted...] Joerg Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Frankie wrote: If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. OTOH, since spam detection mechanisms are not perfect (and black lists based ones are evil), rejecting means you can lose good emails, while with filtering you give yourself (and your users) an option to look at the spam folder from time to time to see if a good message has been flagged as a false positive. Bye -- Que les importa a las viudas, a los huérfanos, a los desvalidos si las masacres se hacen en nombre del totalitarismo o en el sagrado nombre de la libertad y la democracia. Mahatma Gandhi (1869 - 1948) pgp0.pgp Description: PGP signature
RE: [expert] Using Postfix to send mail.
yup, right you are... but you can set spamassassin to only reject mail over a certain threshold, and just tag the rest as spam.. I have mine setup to quarantine spam with a score over 20.. and it has yet to catch any non spam. (I have tagging setup to 4.5 or over) I am only using quarintine at the moment so I can make sure its all good. and so far, (about 80,000 mails have gone through it) its all been good. Since in order to do rejects the proxy has already received the mail in order to scan it, its probably possible to have it saved to a quaranteen dir as well. That way you could retrieve mail if it was mis assigned. Obviously you would play with the tag/reject numbers till you find a good compromise.. and it wouldn't reject all spam.. but it would get the worst ones..and with bayes, it will reject any that you know are spam. regards Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Luca Olivetti Sent: Thursday, 24 July 2003 1:10 AM To: [EMAIL PROTECTED] Subject: Re: [expert] Using Postfix to send mail. Frankie wrote: If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. OTOH, since spam detection mechanisms are not perfect (and black lists based ones are evil), rejecting means you can lose good emails, while with filtering you give yourself (and your users) an option to look at the spam folder from time to time to see if a good message has been flagged as a false positive. Bye -- Que les importa a las viudas, a los huérfanos, a los desvalidos si las masacres se hacen en nombre del totalitarismo o en el sagrado nombre de la libertad y la democracia. Mahatma Gandhi (1869 - 1948) Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
RE: [expert] Using Postfix to send mail.
ok, well when i get some time, I will knock up a howtoo.. (and put it on the twiki) but in answer to one of Joerg's question go to the postfix site and grab the latest snapshot. there is some documentation on the proxy methods. (also the postfix mailing list archives.) rgds Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James Sparenberg Sent: Thursday, 24 July 2003 1:07 AM To: Expert List Subject: Re: [expert] Using Postfix to send mail. On Wed, 2003-07-23 at 04:59, Joerg Mertin wrote: Hia there, so - actually - the new possibility with the Proxy sounds quite interesting, and are what I was looking for a long time now. Does anyone has some hints as what I'd need for it (which version of Postfix would be required), and some examples - on how to configure all that ? Of course - a detailed HOWTO would be best :) And of course ... post it in the community TWiki *grin* Thx for all your Input folks :) On Wednesday 23 July 2003 12:46, Frankie wrote: [...lots of intersting stuff deleted...] Joerg Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Thx Franki, I'll give it a try. Right now - on all the Mails I have seen tagged as Spam, and I also asked all users to check the Spam-Mails they have received - It didn't happen so far - that a non-Spam Mail was tagged as Spam. Rather the other way around - that Spam-Mail got undetected through the Spam-Filter (I don't know yet of an Easy way to tell Spamassassin that this is a Spam ? (Got version 2.55 :)... Specially some Mails are created where all Tag-Words are disguised - as we use to disguise E-Mails... [EMAIL PROTECTED]@ or only a Gif-File containing the entire Message. Has anyone of you automatised Spamassassin - to manually tag undetected Mails ? I mean - having a alias tagspam pointing to user filter filter - that the spamd/spamc are running on - you bounce a Mail to - and the script knows - that everything coming through here _is_ spam - so the bayes part can learn something. Anyone of you folks did that already - or will I have to do it myself ;) So - I am quite confident that losses would be minimal if I save them on a Local Directory. Cheers Joerg On Wednesday 23 July 2003 21:15, Frankie wrote: ok, well when i get some time, I will knock up a howtoo.. (and put it on the twiki) but in answer to one of Joerg's question go to the postfix site and grab the latest snapshot. there is some documentation on the proxy methods. (also the postfix mailing list archives.) rgds Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of James Sparenberg Sent: Thursday, 24 July 2003 1:07 AM To: Expert List Subject: Re: [expert] Using Postfix to send mail. On Wed, 2003-07-23 at 04:59, Joerg Mertin wrote: Hia there, so - actually - the new possibility with the Proxy sounds quite interesting, and are what I was looking for a long time now. Does anyone has some hints as what I'd need for it (which version of Postfix would be required), and some examples - on how to configure all that ? Of course - a detailed HOWTO would be best :) And of course ... post it in the community TWiki *grin* Thx for all your Input folks :) On Wednesday 23 July 2003 12:46, Frankie wrote: [...lots of intersting stuff deleted...] Joerg -- It is better to have loved and lost than just to have lost. | Joerg Mertin : [EMAIL PROTECTED](Home)| | in Neuchâtel/Schweiz : [EMAIL PROTECTED] (Alt1)| | Stardust's LiNUX System : [EMAIL PROTECTED](Alt2)| | Web: http://www.solsys.org: Voice Fax: +41(0)32 / 725 52 54 | PGP Fingerprint: AF0F FB75 997B 025F 4538 5AD6 9888 5D97 170B 8B7A Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
RE: [expert] Using Postfix to send mail.
Hi Joerg, I setup two local user accounts on the server.. ham and spam. anyone that gets incorrectly detected ham or spam can resend it to the spam or ham accounts on the server.. and I run a crontabs to process the ham and spam and use it to create the bayes DB. /usr/bin/sa-learn --spam --mbox /var/spool/mail/spam and /usr/bin/sa-learn --ham --mbox /var/spool/mail/ham (I run that as user amavis.) That way any incorrectly detected mail can be fed back to bayes and told what it should be. seems to work great. One thing you are going to have to do though, is educate your users on resending or redirecting mail as opposed to forwarding it which changes the headers. regards Franki -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Joerg Mertin Sent: Thursday, 24 July 2003 5:00 AM To: [EMAIL PROTECTED] Subject: Re: [expert] Using Postfix to send mail. Thx Franki, I'll give it a try. Right now - on all the Mails I have seen tagged as Spam, and I also asked all users to check the Spam-Mails they have received - It didn't happen so far - that a non-Spam Mail was tagged as Spam. Rather the other way around - that Spam-Mail got undetected through the Spam-Filter (I don't know yet of an Easy way to tell Spamassassin that this is a Spam ? (Got version 2.55 :)... Specially some Mails are created where all Tag-Words are disguised - as we use to disguise E-Mails... [EMAIL PROTECTED]@ or only a Gif-File containing the entire Message. Has anyone of you automatised Spamassassin - to manually tag undetected Mails ? I mean - having a alias tagspam pointing to user filter filter - that the spamd/spamc are running on - you bounce a Mail to - and the script knows - that everything coming through here _is_ spam - so the bayes part can learn something. Anyone of you folks did that already - or will I have to do it myself ;) So - I am quite confident that losses would be minimal if I save them on a Local Directory. Cheers Joerg Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 19:10 schrieb Luca Olivetti: Frankie wrote: If the spam get rejected they know that you don't accept the mail. It is up to the sending server to handle the rejection. OTOH, since spam detection mechanisms are not perfect (and black lists based ones are evil), rejecting means you can lose good emails, while with filtering you give yourself (and your users) an option to look at the spam folder from time to time to see if a good message has been flagged as a false positive. Bye Jep, thats why we don't delete spam. there was some valid mails (it is realy spam too, but the receiver has subscribed to this list) droped by spamassassin. So we tag all spam and every user can set up a filter to delete the spam by a level she/he wants. Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
Re: [expert] Using Postfix to send mail.
On Tue, 22 Jul 2003 07:18:01 +0200 Martin Fahrendorf [EMAIL PROTECTED] uttered: So, you may know that your server is save, but the rest of the wold only may guess. And you are not able to give a guarantee. Your server can not get prooven while changing the IP address. Point taken. Very good explanation. Anyhow, thanks for any assistance! So, in the beginnig, configure your mailserver to use the mailserver of your ISP as a relay. Please see the postfix FAQ on www.postfix.org. There are some config examples for this special needs. Thanks for your time to explain, I'll stick with my ISP til I know more what I am doing. From reading the Postfix FAQ (yes I did!), it seems I need to know a *lot* more about DNS and MX records. Cheers! -- Joehill Registered Linux user #282046 Homepage: nodex.sytes.net ++ 07:28:17 up 6:58, 1 user, load average: 0.00, 0.00, 0.00 God instructs the heart, not by ideas, but by pains and contradictions. -- De Caussade Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On Tue, 22 Jul 2003 06:48:07 -0500 stefmit [EMAIL PROTECTED] uttered: I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. Well, I use www.no-ip.com, I still do not own a domain name. Would that be sufficient? Also, I am not sure what you mean by fixing the IP on my firewall (www.bbiagent.net). Thanks for the tips! -- Joehill Registered Linux user #282046 Homepage: nodex.sytes.net ++ 08:06:07 up 7:35, 1 user, load average: 0.20, 0.18, 0.08 You can always pick up your needle and move to another groove. -- Tim Leary Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On Tuesday 22 July 2003 12:18 am, Martin Fahrendorf wrote: Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, I am on a small internal LAN which does not use a Domain name or even have a DNS server, well, except for the router in a way I suppose. Anyway, I want to try to use my mailserver, simply called localhost, to send mail out rather than my ISP's smtp server. Mainly a learning exercise, you know, start small and all that. I have used sendmail in the past and run into several problems wherein receiving domains see me as an open relay and bounce the mail back to me as potential spam. They don't do it weil because they see you as an open relay but because you have a dynamic IP address and those addresses were missused for spaming. They take the easy way and block whole known dynamic IP address ranges (It is something like that: oh, there are drivers of rented cars who can not drive so to be sure none of those drivers get on our roads lets block our roads to all rented cars). I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. Stef Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Dienstag, 22. Juli 2003 13:48 schrieb stefmit: On Tuesday 22 July 2003 12:18 am, Martin Fahrendorf wrote: Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, ... I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. It is a little bit of both. Some dynamic IP addresses will be blocked because they are dynamic and some don't. The forward and reverse lookup is a complete different thing. every ip address and domain in e-mail traffic must be forward and reverse resolvable. sometimes it works without, but most of the time it don't. Stef Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
Re: [expert] Using Postfix to send mail.
On Tuesday 22 July 2003 07:08 am, JoeHill wrote: On Tue, 22 Jul 2003 06:48:07 -0500 stefmit [EMAIL PROTECTED] uttered: I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. Well, I use www.no-ip.com, I still do not own a domain name. Would that be sufficient? Give it a try - won't hurt ... Also, I am not sure what you mean by fixing the IP on my firewall (www.bbiagent.net). I grabbed the first address they gave me (i.e. which was dynamically assigned, when I first got the service), set it up as static on the external interface of my firewall, and haven't seen it changed since ;) This is how I got to have a site-to-site VPN with my workplace ... One thing a friend of mine had to do, with his provider (I never had that problem!) was to not block ICMP echo/replies, as his provider was scavenging for available addresses, before giving them out ... once his would reply, he would keep it, but if blocking ICMP, his connectivity would stop (when I say scavenging I imply any methods, including the mechanisms of DCHP, not necessarily provider's own scripts and such). For the other comment from Martin: I do not disagree with the fact that some may rely on both IP address and reverse lookup ... but it's been my experience with big providers (thus owners of bigger pools of addresses, e.g. CW or Qwest) of them using their leverage against those trying to use IP-filtering, because that may affect some commercial entities. We went through such a thing at my workplace, where a phone call to a recipient blocking IPs clarified the fact that we had high numbers of Sales Offices with static assignments, from the same pool as the ones used by the same broadband providers for regular customers (i.e. dynamically assigned). In the end they removed the IP-blocking, and relied on reverse lookup with proper domain naming (i.e. blocking only those which would resolve in something like ip-address.client.attbi.com, for example) ... Good luck, Stef Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On Tue, 2003-07-22 at 06:28, Martin Fahrendorf wrote: Am Dienstag, 22. Juli 2003 13:48 schrieb stefmit: On Tuesday 22 July 2003 12:18 am, Martin Fahrendorf wrote: Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, ... I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. It is a little bit of both. Some dynamic IP addresses will be blocked because they are dynamic and some don't. The forward and reverse lookup is a complete different thing. every ip address and domain in e-mail traffic must be forward and reverse resolvable. sometimes it works without, but most of the time it don't. Stef The other thing I've run into..(Mainly with gnu list serv lists.) is that apparently the RFC requires that [EMAIL PROTECTED] exist. If it doesn't they will refuse all e-mail, Even if you have reverse DNS etc. Great idea now I'm guaranteed to have an e-mail address spammers can send to. James Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Dienstag, 22. Juli 2003 20:56 schrieb James Sparenberg: On Tue, 2003-07-22 at 06:28, Martin Fahrendorf wrote: Am Dienstag, 22. Juli 2003 13:48 schrieb stefmit: On Tuesday 22 July 2003 12:18 am, Martin Fahrendorf wrote: Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, ... I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. It is a little bit of both. Some dynamic IP addresses will be blocked because they are dynamic and some don't. The forward and reverse lookup is a complete different thing. every ip address and domain in e-mail traffic must be forward and reverse resolvable. sometimes it works without, but most of the time it don't. Stef The other thing I've run into..(Mainly with gnu list serv lists.) is that apparently the RFC requires that [EMAIL PROTECTED] exist. If it doesn't they will refuse all e-mail, Even if you have reverse DNS etc. Great idea now I'm guaranteed to have an e-mail address spammers can send to. It is not only this address. There are some more. If you dont hav all these addresses enabled you can find your server on a list of rfc-ignorant.org. There are som mail server outside which don't accept mails from servers listed in rfc-ignorant.org. But on the other hand, if you have problems with one Mailserver how can you inform the server administrator if the postmaster mailbox does not exists? BTW, in the last four years, I haven't got any spam on the postmaster mailbox. James Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
Re: [expert] Using Postfix to send mail.
On Tue, 2003-07-22 at 22:04, Martin Fahrendorf wrote: Am Dienstag, 22. Juli 2003 20:56 schrieb James Sparenberg: On Tue, 2003-07-22 at 06:28, Martin Fahrendorf wrote: Am Dienstag, 22. Juli 2003 13:48 schrieb stefmit: On Tuesday 22 July 2003 12:18 am, Martin Fahrendorf wrote: Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, ... I have the same setup at home (postfix for localhost, and dynamically assigned address), and what I found out from some receiving systems/ISPs was that they were rejecting my email not because of the membership to a specific pool of addresses, but rather because of the reverse lookup, that would either fail, or be dynamically associated with broadband or dial-up domains. The moment I registered my domain, and pointed back to my IP address (which - by the way - as dynamic as it was advertised, I just fixed it on my firewall, and never had a problem ;)), all emails started flowing just fine, regardless of the pool of IPs I was part of ... so check out this alternative, also. It is a little bit of both. Some dynamic IP addresses will be blocked because they are dynamic and some don't. The forward and reverse lookup is a complete different thing. every ip address and domain in e-mail traffic must be forward and reverse resolvable. sometimes it works without, but most of the time it don't. Stef The other thing I've run into..(Mainly with gnu list serv lists.) is that apparently the RFC requires that [EMAIL PROTECTED] exist. If it doesn't they will refuse all e-mail, Even if you have reverse DNS etc. Great idea now I'm guaranteed to have an e-mail address spammers can send to. It is not only this address. There are some more. If you dont hav all these addresses enabled you can find your server on a list of rfc-ignorant.org. There are som mail server outside which don't accept mails from servers listed in rfc-ignorant.org. But on the other hand, if you have problems with one Mailserver how can you inform the server administrator if the postmaster mailbox does not exists? BTW, in the last four years, I haven't got any spam on the postmaster mailbox. Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Mittwoch, 23. Juli 2003 07:35 schrieb James Sparenberg: On Tue, 2003-07-22 at 22:04, Martin Fahrendorf wrote: Am Dienstag, 22. Juli 2003 20:56 schrieb James Sparenberg: ... But on the other hand, if you have problems with one Mailserver how can you inform the server administrator if the postmaster mailbox does not exists? BTW, in the last four years, I haven't got any spam on the postmaster mailbox. Don't doubt you on this ... but if you are feeling left out ... I can send you some of what we get *grin*. James No thanks. I fight spam as much as possible. And the next version of postfix will make it a little bit easier to reject spam. Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
[expert] Using Postfix to send mail.
Hello, I am on a small internal LAN which does not use a Domain name or even have a DNS server, well, except for the router in a way I suppose. Anyway, I want to try to use my mailserver, simply called localhost, to send mail out rather than my ISP's smtp server. Mainly a learning exercise, you know, start small and all that. I have used sendmail in the past and run into several problems wherein receiving domains see me as an open relay and bounce the mail back to me as potential spam. I a looking at the postfix docs right now, and I am confused about a few things. In my mail client, I choose sendmail for sending mail, but how does this relate to Postfix? Does Postfix simply receive all commands from sendmail and process them? If so, how to I configure Postfix (I am assuming this is in /etc/postfix/main.cf) to let receivers know I am not an open relay and they have nothing to fear from me. I read in the docs that by default Postfix will not relay mail by default, so I rest easy that I am *not* an open relay, correct? Anyhow, thanks for any assistance! -- Joehill Registered Linux user #282046 Homepage: nodex.sytes.net ++ 16:11:35 up 8:36, 3 users, load average: 0.11, 0.10, 0.13 Do not seek death; death will find you. But seek the road which makes death a fulfillment. -- Dag Hammarskjold Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Using sendmail to send your email automatically will use postfix by default on your system. Postfix understands sendmail. As for using localhost, that may be fine for testing, and it will be the default if you haven't made any changes or named your system something else but it would be better to use a name. I haven't messed with postfix for a while but you will be able to send emails to individuals and newsgroups, etc, via postfix using localhost or any other name you set but you wont be able to post to this mailing list or any other (as far as I know) and people who receive the email wont be able to reply to it because localhost is not valid. You would also run into problems if you made up a name because any attempt by others to reply to any such email would fail because your domain name would not be in any dns table. My hostname on my laptop is lapdog.ravenhome.net. I own the ravenhome.net domain name (paid for it for several years and will have to then renew). My desktop has a different hostname in the same domain. I use dyndns and ddclient to keep the dns servers updated as to my IP (dynamic IP via dhcp). With this, I can use postfix and append my domain name to my username and send emails anywhere and run into no problems. People could reply and it would get to me just fine. What you want to do, playing around to learn, would work locally but, again, any test email to any host but your own would not be able to be replied to (as a second half of the test). Postfix, by default, is not setup as an open relay. This wouldn't even come up unless spammers were passing messages through your mailserver anyway, which they couldn't. In any case, you should look into paying for a domain name (not expensive...something like $20-$30 as I recall for 3 years or so). You could then make a legit personal email address that is actually able to be replied to. Of course, you could also set yourself up with a reply-to address to get around part of the problem with [EMAIL PROTECTED] or [EMAIL PROTECTED]. praedor On Monday 21 July 2003 03:18 pm, JoeHill wrote: Hello, I am on a small internal LAN which does not use a Domain name or even have a DNS server, well, except for the router in a way I suppose. Anyway, I want to try to use my mailserver, simply called localhost, to send mail out rather than my ISP's smtp server. Mainly a learning exercise, you know, start small and all that. I have used sendmail in the past and run into several problems wherein receiving domains see me as an open relay and bounce the mail back to me as potential spam. I a looking at the postfix docs right now, and I am confused about a few things. In my mail client, I choose sendmail for sending mail, but how does this relate to Postfix? Does Postfix simply receive all commands from sendmail and process them? If so, how to I configure Postfix (I am assuming this is in /etc/postfix/main.cf) to let receivers know I am not an open relay and they have nothing to fear from me. I read in the docs that by default Postfix will not relay mail by default, so I rest easy that I am *not* an open relay, correct? Anyhow, thanks for any assistance! - -- Not a single 9/11 terrorist came from Iraq, nor did a single one train in Iraq. Iraq had NOTHING to do with 9/11. -BEGIN PGP SIGNATURE- Version: GnuPG v1.2.2 (GNU/Linux) iD8DBQE/HFpYaKr9sJYeTxgRAn+aAKCQz0monbRRgkZwR4sy8SXgiKUZmwCgmT+i Nst1RPLujzd+FwT0dOKvJwo= =KRX0 -END PGP SIGNATURE- Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
On Mon, 21 Jul 2003 16:25:37 -0500 Praedor Atrebates [EMAIL PROTECTED] uttered: I haven't messed with postfix for a while but you will be able to send emails to individuals and newsgroups, etc, via postfix using localhost or any other name you set but you wont be able to post to this mailing list or any other (as far as I know) and people who receive the email wont be able to reply to it because localhost is not valid. You would also run into problems if you made up a name because any attempt by others to reply to any such email would fail because your domain name would not be in any dns table. Short version, I should just keep using my ISP to send until I get more of a grip on DNS and my own domain... Thanks for the very informative reply! -- Joehill Registered Linux user #282046 Homepage: nodex.sytes.net ++ 18:40:31 up 11:05, 5 users, load average: 0.27, 0.21, 0.08 He who despairs over an event is a coward, but he who holds hopes for the human condition is a fool. -- Albert Camus Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
Re: [expert] Using Postfix to send mail.
Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: Hello, I am on a small internal LAN which does not use a Domain name or even have a DNS server, well, except for the router in a way I suppose. Anyway, I want to try to use my mailserver, simply called localhost, to send mail out rather than my ISP's smtp server. Mainly a learning exercise, you know, start small and all that. I have used sendmail in the past and run into several problems wherein receiving domains see me as an open relay and bounce the mail back to me as potential spam. They don't do it weil because they see you as an open relay but because you have a dynamic IP address and those addresses were missused for spaming. They take the easy way and block whole known dynamic IP address ranges (It is something like that: oh, there are drivers of rented cars who can not drive so to be sure none of those drivers get on our roads lets block our roads to all rented cars). I a looking at the postfix docs right now, and I am confused about a few things. In my mail client, I choose sendmail for sending mail, but how does this relate to Postfix? Does Postfix simply receive all commands from sendmail and process them? postfix has a sanemail compatibility layer. the postfix/sendmail has nothing to do with the sendmail program. It is only called the same. There are some programs out there which needs a programm called sendmail with the known functionality of the famous sendmail. If so, how to I configure Postfix (I am assuming this is in /etc/postfix/main.cf) to let receivers know I am not an open relay and they have nothing to fear from me. You can not. All the big ISP which reject your mails don't care wether you can send mails from your own mailserver or not. I read in the docs that by default Postfix will not relay mail by default, so I rest easy that I am *not* an open relay, correct? It is not that easy. To run a mailserver is mor than to install postfix. you are responsible for your configuration and your users who are allowed to use your mailserver. And there are so many poor installed and configured mailserver out there. It is hard to collect all this servers with static ip addresses, but with dynamic addresses it is not possible. And, your intention may be not to build a open relay, but are you shure you ar the only person, who is able to configure your server? So, you may know that your server is save, but the rest of the wold only may guess. And you are not able to give a guarantee. Your server can not get prooven while changing the IP address. Anyhow, thanks for any assistance! So, in the beginnig, configure your mailserver to use the mailserver of your ISP as a relay. Please see the postfix FAQ on www.postfix.org. There are some config examples for this special needs. Martin -- H E L I X Gesellschaft für Software Engineering mbH Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 http://www.helix-gmbh.net[EMAIL PROTECTED] pgp0.pgp Description: signature
