Re: murphy in sbl.spamhaus.org
On Friday 26 November 2004 03.34, Stephen Frost wrote: > * Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: > > > > And, of course, postgrey as the very first line of defense. > > > > Coupled with the usual checking on HELO (blocking 'localhost' HELOs and > > my own IP does wonders!), SMTP protocol conformance (pipelining), > > sender (envelope) address checking. > > Things which increase the load on the remote mail servers are *bad*. > That would include responding with temporary errors unnecessairly and > adding unnecessary delays in communication. pipelining by itself isn't > necessairly terrible- adding things like 2 minute delays is bad though. I'm happy to queue my outgoing email if the remote end uses greylisting, as I expect the remote site to queue my incoming mail with my greylisting. Add to the the fact that amongst the mail senders big enough so that the queue size matters are probably many of those ISPs with badly policed (DSL/cable) network, operating the spam zombies which cause me to use greylisting in the first place... About pipelining: what postfix does is enforce proper use of pipelining: the sender may only start pipelining requests when it has actually seen that postfix does support pipelining. Regular mail servers never notice this, but some stupid spammers just push the request out without waiting for responses at all - these are rejected. -- vbi -- TODO: apt-get install signify pgpfp7vTpvIYg.pgp Description: PGP signature
Re: murphy in sbl.spamhaus.org
On Fr, 26.11.2004, 03:34, Stephen Frost wrote: > * Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: >> >> And, of course, postgrey as the very first line of defense. >> >> Coupled with the usual checking on HELO (blocking 'localhost' HELOs and >> my >> own IP does wonders!), SMTP protocol conformance (pipelining), sender >> (envelope) address checking. > > Things which increase the load on the remote mail servers are *bad*. > That would include responding with temporary errors unnecessairly and > adding unnecessary delays in communication. pipelining by itself isn't > necessairly terrible- adding things like 2 minute delays is bad though. What about greylisting depending on results of e.g. SA? Only above a limit of scores from SA greylisting would be become active. Christian -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
* Christian Storch: >> Things which increase the load on the remote mail servers are *bad*. >> That would include responding with temporary errors unnecessairly and >> adding unnecessary delays in communication. pipelining by itself isn't >> necessairly terrible- adding things like 2 minute delays is bad though. > > What about greylisting depending on results of e.g. SA? > Only above a limit of scores from SA greylisting would be become active. This is very impolite because it requires that the entire message is transferred at least twice. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
On Fri, Nov 26, 2004 at 10:04:38AM +0100, Christian Storch wrote: > What about greylisting depending on results of e.g. SA? > Only above a limit of scores from SA greylisting would be become active. Use as many RBLs instead of the SA score, but use them not for blocking but for activating greylisting, teergrubing and non-pipelining/synch-checks. All these actions effectivly block ratware but by using the RBLs you can avoid hitting the delays on real MTAs. Regards, David -- * Customer: "My palmtop won't turn on." * Tech Support: "Did the battery run out, maybe?" * Customer: "No, it doesn't use batteries. It's Windows powered." -- http://www.rinkworks.com/stupid/cs_power.shtml -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
On Fri, Nov 26, 2004 at 10:57:31AM +0100, Florian Weimer wrote: >* Christian Storch: > >>> Things which increase the load on the remote mail servers are *bad*. >>> That would include responding with temporary errors unnecessairly and >>> adding unnecessary delays in communication. pipelining by itself isn't >>> necessairly terrible- adding things like 2 minute delays is bad though. >> >> What about greylisting depending on results of e.g. SA? >> Only above a limit of scores from SA greylisting would be become active. > >This is very impolite because it requires that the entire message is >transferred at least twice. I thought greylisting closes the smtp connection with a temporary failure immediately to unfamiliar routers. Then they can transmit the message on a second attempt, but since spam relays don't queue, they won't try again. // George -- George Georgalis, systems architect, administrator Linux BSD IXOYE http://galis.org/george/ cell:646-331-2027 mailto:[EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
George Georgalis schrieb/wrote/a écrit/escribió: > On Fri, Nov 26, 2004 at 10:57:31AM +0100, Florian Weimer wrote: > >* Christian Storch: > >> What about greylisting depending on results of e.g. SA? > >> Only above a limit of scores from SA greylisting would be become active. > >This is very impolite because it requires that the entire message is > >transferred at least twice. > I thought greylisting closes the smtp connection with a temporary > failure immediately to unfamiliar routers. Then they can transmit the > message on a second attempt, but since spam relays don't queue, they > won't try again. Chrisitan proposed greylisting based on SA scores - that requires the messages to be transmitted before rejecting them the first time (with an temporary error), and then to be transmitted again. It's a matter of time til the spammers begin to implement queues in their spamware (on some infected Windows zombies). Greylisting is obsolete then. pgpPPnWcUtG40.pgp Description: PGP signature
zip sarge's package vulnerable to CAN-2004-1010
Hello, Current CAN-2004-1010 was fixed on zip 2.30-8 but current sarge version still vulnerable. This package need to be included on sarge to solve it. Thanks in advance, Otavio -- O T A V I OS A L V A D O R - E-mail: [EMAIL PROTECTED] UIN: 5906116 GNU/Linux User: 239058 GPG ID: 49A5F855 Home Page: http://www.freedom.ind.br/otavio - "Microsoft gives you Windows ... Linux gives you the whole house." pgpbVo2rLESj4.pgp Description: PGP signature
Re: murphy in sbl.spamhaus.org
* Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: > On Friday 26 November 2004 03.34, Stephen Frost wrote: > > * Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: > > > > > > And, of course, postgrey as the very first line of defense. > > > > > > Coupled with the usual checking on HELO (blocking 'localhost' HELOs and > > > my own IP does wonders!), SMTP protocol conformance (pipelining), > > > sender (envelope) address checking. > > > > Things which increase the load on the remote mail servers are *bad*. > > That would include responding with temporary errors unnecessairly and > > adding unnecessary delays in communication. pipelining by itself isn't > > necessairly terrible- adding things like 2 minute delays is bad though. > > I'm happy to queue my outgoing email if the remote end uses greylisting, as > I expect the remote site to queue my incoming mail with my greylisting. That's nice, obviously you don't handle much mail. > Add to the the fact that amongst the mail senders big enough so that the > queue size matters are probably many of those ISPs with badly policed > (DSL/cable) network, operating the spam zombies which cause me to use > greylisting in the first place... That's a *terrible* and just plain stupid assumption. Queue size makes a difference to me, both on a machine I run for some friends and in the part-time work that I do for a small ISP (which, hey, doesn't even provide DSL or cable modem service). Queue size matters to universities who are draconian about their policing, and I'm sure it matters to the 'good' ISPs too. Let me tell you that if you use that greylisting crap against the servers that *I* run your mail will get dumped into a secondary queue which is processed at a much slower rate. I won't slow things down for others because of a few idiots who can't figure out how to configure their mail servers. > About pipelining: what postfix does is enforce proper use of pipelining: the > sender may only start pipelining requests when it has actually seen that > postfix does support pipelining. Regular mail servers never notice this, > but some stupid spammers just push the request out without waiting for > responses at all - these are rejected. That'd be why I said that pipelineing isn't really an issue but adding in random unnecessary delays is bad, which is something that's been advocated in a number of places and ends up increasing the load on my mail servers. Stephen signature.asc Description: Digital signature
Re: zip sarge's package vulnerable to CAN-2004-1010
On Fri, Nov 26, 2004 at 05:21:03PM -0200, Otavio Salvador wrote: > Current CAN-2004-1010 was fixed on zip 2.30-8 but current sarge > version still vulnerable. This package need to be included on sarge to > solve it. zip 2.30-8 is already in sarge: zip | 2.30-8 | testing | source, alpha, arm, hppa, i386, ia64, m68k, mips, mipsel, powerpc, s390, sparc zip | 2.30-8 | unstable | source, alpha, arm, hppa, i386, ia64, m68k, mips, mipsel, powerpc, s390, sparc Cheers, -- Colin Watson [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: zip sarge's package vulnerable to CAN-2004-1010
On Fri, Nov 26, 2004 at 05:21:03PM -0200, Otavio Salvador wrote: > Current CAN-2004-1010 was fixed on zip 2.30-8 but current sarge > version still vulnerable. This package need to be included on sarge to > solve it. It already has been. -- Steve Langasek postmodern programmer signature.asc Description: Digital signature
Re: murphy in sbl.spamhaus.org
This one time, at band camp, Stephen Frost said: > * Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: > > On Friday 26 November 2004 03.34, Stephen Frost wrote: > > > * Adrian 'Dagurashibanipal' von Bidder ([EMAIL PROTECTED]) wrote: > > > > > > > > And, of course, postgrey as the very first line of defense. > > > > > > Things which increase the load on the remote mail servers are *bad*. > > > That would include responding with temporary errors unnecessairly and > > > adding unnecessary delays in communication. Things which slow down my MTA are equally bad. > > Add to the the fact that amongst the mail senders big enough so that the > > queue size matters are probably many of those ISPs with badly policed > > (DSL/cable) network, operating the spam zombies which cause me to use > > greylisting in the first place... > > That's a *terrible* and just plain stupid assumption. Queue size makes > a difference to me, both on a machine I run for some friends and in the > part-time work that I do for a small ISP (which, hey, doesn't even > provide DSL or cable modem service). Queue size matters to universities > who are draconian about their policing, and I'm sure it matters to the > 'good' ISPs too. Of course queue size matters. I don't think that's what he's saying though. He's saying that those organizations that are that big are also a source of a lot fo the spam flying about. Not %100 true, but there is some correlation. A sensible greylisting scheme will auto-whitelist a sending IP after so many whitelisted entries (successful retries) - the only point of greylisting is that we know that the remote end won't retry in most cases. Once it's been shown that they do retry, why bother greylisting them anymore? If you do implement this sort of scheme, any extra load you place on the remote end is transient, and will go away shortly, never to be repeated. It's not really a large price to pay for a pretty effective tool. > Let me tell you that if you use that greylisting crap against the > servers that *I* run your mail will get dumped into a secondary queue > which is processed at a much slower rate. I won't slow things down for > others because of a few idiots who can't figure out how to configure > their mail servers. Take a deep breath, and count to ten. I handle some fairly large mail installations at work, and greylisting has been of tremendous benefit to us. If it's done sensibly (as above) it does transiently increase load on remote MTA's for a couple of days until the common sending IPs have been whitelisted, and then it settles back down. > > About pipelining: what postfix does is enforce proper use of pipelining: > > the > > sender may only start pipelining requests when it has actually seen that > > postfix does support pipelining. Regular mail servers never notice this, > > but some stupid spammers just push the request out without waiting for > > responses at all - these are rejected. > > That'd be why I said that pipelineing isn't really an issue but adding > in random unnecessary delays is bad, which is something that's been > advocated in a number of places and ends up increasing the load on my > mail servers. Introducing delays is usually only advocated for fairly egregious and obvious spam-like tactics (HELO as my IP/hostname, etc). If you're doing that, then you deserve to be a little overloaded. If you're running a reasonably sensible MTA, then you should never trip those kinds of checks. If people are delaying a sensible MTA, then they deserve to be LART'ed for doing something silly, but the practice itself isn't unreasonable. -- - | ,''`.Stephen Gran | | : :' :[EMAIL PROTECTED] | | `. `'Debian user, admin, and developer | |`- http://www.debian.org | - pgprmOgfdY15j.pgp Description: PGP signature
bad md5's on ftp.us.debian.org ?
Below are the errors reported by apt-get update. Is this correct? Could someone explain please? Thanks. === 16:35 CST 2004-11-26 Failed to fetch http://ftp.us.debian.org/debian/dists/sarge/main/binary-i386/Packages.gz MD5Sum mismatch Failed to fetch http://ftp.us.debian.org/debian/dists/sarge/main/source/Sources.gz MD5Sum mismatch Failed to fetch http://ftp.us.debian.org/debian/dists/testing/main/binary-i386/Packages.gz MD5Sum mismatch Failed to fetch http://ftp.us.debian.org/debian/dists/testing/main/source/Sources.gz MD5Sum mismatch Failed to fetch http://ftp.us.debian.org/debian/dists/unstable/main/binary-i386/Packages.gz MD5Sum mismatch Failed to fetch http://ftp.us.debian.org/debian/dists/unstable/non-free/binary-i386/Packages.gz MD5Sum mismatch -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Serious problem after tetex security update
Hi! After the last security update with libkpathsea3 and tetex-bin my LaTeX installation doesn't work any more. When I try to compile a LaTeX file I get: I can't find the format file `latex.fmt'! What can I do to get a working LaTeX installation back? I urgently need it! Thanks a lot in advance! Andreas Goesele -- Omnis enim res, quae dando non deficit, dum habetur et non datur, nondum habetur, quomodo habenda est. Augustinus, De doctrina christiana -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Serious problem after tetex security update
Andreas Goesele <[EMAIL PROTECTED]> writes: > After the last security update with libkpathsea3 and tetex-bin my > LaTeX installation doesn't work any more. When I try to compile a > LaTeX file I get: > > I can't find the format file `latex.fmt'! > > What can I do to get a working LaTeX installation back? I urgently > need it! I found the solution. There is a bug in the new package: /usr/share/texmf/web2c does not link to /var/lib/texmf/web2c (as it should) but to /var/lib/texmf/web2 (note the missing c). As a result the link wasn't even created in my case. (There was no /usr/share/texmf/web2c after the security update.) Is it enough to report that here, or should I report it somewhere else too? Andreas Goesele -- Omnis enim res, quae dando non deficit, dum habetur et non datur, nondum habetur, quomodo habenda est. Augustinus, De doctrina christiana -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Serious problem after tetex security update
On Sat, 27 Nov 2004, Andreas Goesele wrote: > Andreas Goesele <[EMAIL PROTECTED]> writes: > > After the last security update with libkpathsea3 and tetex-bin my > > LaTeX installation doesn't work any more. When I try to compile a > > LaTeX file I get: > > > > I can't find the format file `latex.fmt'! > > > > What can I do to get a working LaTeX installation back? I urgently > > need it! > > I found the solution. There is a bug in the new package: > > /usr/share/texmf/web2c does not link to /var/lib/texmf/web2c (as it > should) but to /var/lib/texmf/web2 (note the missing c). As a result > the link wasn't even created in my case. (There was no > /usr/share/texmf/web2c after the security update.) > > Is it enough to report that here, or should I report it somewhere else > too? Please use the reportbug tool to file a bug. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Serious problem after tetex security update
Incoming from Andreas Goesele: > Andreas Goesele <[EMAIL PROTECTED]> writes: > > > After the last security update with libkpathsea3 and tetex-bin my > > LaTeX installation doesn't work any more. When I try to compile a > > LaTeX file I get: > > > > I can't find the format file `latex.fmt'! > > > > What can I do to get a working LaTeX installation back? I urgently > > need it! > > I found the solution. There is a bug in the new package: > > /usr/share/texmf/web2c does not link to /var/lib/texmf/web2c (as it Odd. It worked for me (though I haven't tried any LaTeX commands): (0) keeling /home/keeling/.mozilla/plugins_ ls -al /usr/share/texmf/web2c /var/lib/texmf/web2c /var/lib/texmf/web2 ls: /var/lib/texmf/web2: No such file or directory lrwxrwxrwx1 root root 20 Nov 25 11:06 /usr/share/texmf/web2c -> /var/lib/texmf/web2c/ /var/lib/texmf/web2c: total 14315 drwxr-xr-x2 root root 3072 Nov 25 11:07 ./ drwxr-xr-x3 root root 1024 Nov 26 06:30 ../ -rw-r--r--1 root root 5320 Nov 24 01:55 amiga-pl.tcx -rw-r--r--1 root root 405356 Nov 25 11:07 amstex.fmt -rw-r--r--1 root root 3064 Nov 25 11:07 amstex.log ... -- Any technology distinguishable from magic is insufficiently advanced. (*)http://www.spots.ab.ca/~keeling Please don't Cc: me. - - -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Serious problem after tetex security update
## Andreas Goesele ([EMAIL PROTECTED]): > > After the last security update with libkpathsea3 and tetex-bin my > > LaTeX installation doesn't work any more. When I try to compile a > > LaTeX file I get: > > I can't find the format file `latex.fmt'! > > What can I do to get a working LaTeX installation back? I urgently > > need it! > I found the solution. There is a bug in the new package: > /usr/share/texmf/web2c does not link to /var/lib/texmf/web2c (as it > should) but to /var/lib/texmf/web2 (note the missing c). As a result > the link wasn't even created in my case. (There was no > /usr/share/texmf/web2c after the security update.) Just checked, everything fine here (using tetex-bin 1.0.7+20011202-7.3). Regards, Christoph -- Spare Space -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
* Stephen Gran ([EMAIL PROTECTED]) wrote: > This one time, at band camp, Stephen Frost said: > > That's a *terrible* and just plain stupid assumption. Queue size makes > > a difference to me, both on a machine I run for some friends and in the > > part-time work that I do for a small ISP (which, hey, doesn't even > > provide DSL or cable modem service). Queue size matters to universities > > who are draconian about their policing, and I'm sure it matters to the > > 'good' ISPs too. > > Of course queue size matters. I don't think that's what he's saying > though. He's saying that those organizations that are that big are also > a source of a lot fo the spam flying about. Not %100 true, but there is > some correlation. The problem is that it's probably not even 20% true. There really isn't any correlation. There are lots of good ISPs and other service providers who are big enough that queue size matters to them but which aren't sources of spam. > A sensible greylisting scheme will auto-whitelist a sending IP after > so many whitelisted entries (successful retries) - the only point of > greylisting is that we know that the remote end won't retry in most cases. > Once it's been shown that they do retry, why bother greylisting them > anymore? > > If you do implement this sort of scheme, any extra load you place on the > remote end is transient, and will go away shortly, never to be repeated. > It's not really a large price to pay for a pretty effective tool. A system which didn't increase the load on the remote mail servers would be better. Having whitelisting w/ greylisting is better but I still don't like it. What about secondary MX's? How is the greylist going to work with those, a seperate list, or will they be unified? Will it correctly pick up on and whitelist a server that goes for a secondary MX after getting a temporary error at the first? Of course, I've run into people who have had secondary MX's configured incorrectly to the point where it drops mail, or refuses to forward the message on, etc. You can understand that I'd have my doubts about the ability of people to implement a scheme such as this. > > Let me tell you that if you use that greylisting crap against the > > servers that *I* run your mail will get dumped into a secondary queue > > which is processed at a much slower rate. I won't slow things down for > > others because of a few idiots who can't figure out how to configure > > their mail servers. > > Take a deep breath, and count to ten. Hey, it's how my mail servers are configured- if you're too slow to respond or the mail doesn't leave the main queue fast enough for whatever reason it'll get dumped into a slower queue that's run less often. It wasn't a threat. :) > I handle some fairly large mail installations at work, and greylisting > has been of tremendous benefit to us. If it's done sensibly (as above) > it does transiently increase load on remote MTA's for a couple of days > until the common sending IPs have been whitelisted, and then it settles > back down. Perhaps it would have made sense to look at your logs and whitelist those hosts ahead of time. Sounds like you know what you're doing- that wouldn't be hard. > > > About pipelining: what postfix does is enforce proper use of pipelining: > > > the > > > sender may only start pipelining requests when it has actually seen that > > > postfix does support pipelining. Regular mail servers never notice this, > > > but some stupid spammers just push the request out without waiting for > > > responses at all - these are rejected. > > > > That'd be why I said that pipelineing isn't really an issue but adding > > in random unnecessary delays is bad, which is something that's been > > advocated in a number of places and ends up increasing the load on my > > mail servers. > > Introducing delays is usually only advocated for fairly egregious and > obvious spam-like tactics (HELO as my IP/hostname, etc). If you're > doing that, then you deserve to be a little overloaded. If you're > running a reasonably sensible MTA, then you should never trip those > kinds of checks. If people are delaying a sensible MTA, then they > deserve to be LART'ed for doing something silly, but the practice itself > isn't unreasonable. Unfortunately I had someone complain at me that my mail servers kept going to their secondary MX, turns out it was because he had a forced 2 minute delay before responding to HELO and my mail server wasn't waiting around that long. He had it because some website (the mailer was exim, iirc) was advocating it and encouraging people to do it for all incoming connections. The problem is that some people *are* silly, or stupid, and schemes like this often end up misused, misconfigured, and implemented wrong. That's why I don't like them. Stephen signature.asc Description: Digital signature
Re: Serious problem after tetex security update
"s. keeling" <[EMAIL PROTECTED]> writes: > Incoming from Andreas Goesele: >> I found the solution. There is a bug in the new package: >> >> /usr/share/texmf/web2c does not link to /var/lib/texmf/web2c (as it > > Odd. It worked for me (though I haven't tried any LaTeX commands): > > (0) keeling /home/keeling/.mozilla/plugins_ ls -al /usr/share/texmf/web2c > /var/lib/texmf/web2c /var/lib/texmf/web2 > ls: /var/lib/texmf/web2: No such file or directory > lrwxrwxrwx1 root root 20 Nov 25 11:06 > /usr/share/texmf/web2c -> /var/lib/texmf/web2c/ This link wasn't created in my case. But maybe I was wrong about the reason. Just to test it I reinstalled the new package and this time there was no problem. The wrong link to the non-existing /var/lib/texmf/web2 in the package might be irrelevant as the right link should be created by the postinst script. (Anyway, so it seems to me.) No idea why the link wasn't created when I first updated the package. But as long nobody else gets the same problem I assume there is no bug ... Andreas Goesele -- Omnis enim res, quae dando non deficit, dum habetur et non datur, nondum habetur, quomodo habenda est. Augustinus, De doctrina christiana -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: murphy in sbl.spamhaus.org
This one time, at band camp, Stephen Frost said: > * Stephen Gran ([EMAIL PROTECTED]) wrote: > > A sensible greylisting scheme will auto-whitelist a sending IP after > > so many whitelisted entries (successful retries) - the only point of > > greylisting is that we know that the remote end won't retry in most cases. > > Once it's been shown that they do retry, why bother greylisting them > > anymore? > > > > If you do implement this sort of scheme, any extra load you place on the > > remote end is transient, and will go away shortly, never to be repeated. > > It's not really a large price to pay for a pretty effective tool. > > A system which didn't increase the load on the remote mail servers would > be better. Having whitelisting w/ greylisting is better but I still > don't like it. What about secondary MX's? How is the greylist going to > work with those, a seperate list, or will they be unified? Will it > correctly pick up on and whitelist a server that goes for a secondary MX > after getting a temporary error at the first? Of course, I've run into > people who have had secondary MX's configured incorrectly to the point > where it drops mail, or refuses to forward the message on, etc. You can > understand that I'd have my doubts about the ability of people to > implement a scheme such as this. I wouldn't really advocate using secondary MX's these days, and certainly not ones not ones not under your control. If you need redundancy, I'd use a load balancer with a server farm behind it. They can all share access to the same database for greylisting purposes that way, and you get better failover. Secondary MX's tend to just be spam targets and rarely serve any real use. If you must have a seperate secondary MX (you don't have the hardware resources, or whatever) I would really strongly advocate that you find a way to get a list of valid users from the primary onto the secondary - all the bounces when the primary comes back up and spam starts failing are part of the problem. > > I handle some fairly large mail installations at work, and greylisting > > has been of tremendous benefit to us. If it's done sensibly (as above) > > it does transiently increase load on remote MTA's for a couple of days > > until the common sending IPs have been whitelisted, and then it settles > > back down. > > Perhaps it would have made sense to look at your logs and whitelist > those hosts ahead of time. Sounds like you know what you're doing- that > wouldn't be hard. We did pre-whitelist about 50 or so known good hosts, determined the old-fashioned way, with grep, sed, sort, and uniq -c. As always, we missed several, but they got added automagically. This is one of those situations where it is hard to always know programatically what's going to come up, and so that's where the importance of an auto whitelister come in. For instance, we had almost no hits from Southwest airlines MX before the switchover, and then they opened a hub in Philadelphia. We started getting a ton of emails from them, since they're so cheap - they're the US answer to Ryan air. They also happen to use VERP for their notification emails, so _all_ of their mail was delayed until the auto whitelister added them after a day or two. > > Introducing delays is usually only advocated for fairly egregious and > > obvious spam-like tactics (HELO as my IP/hostname, etc). If you're > > doing that, then you deserve to be a little overloaded. If you're > > running a reasonably sensible MTA, then you should never trip those > > kinds of checks. If people are delaying a sensible MTA, then they > > deserve to be LART'ed for doing something silly, but the practice itself > > isn't unreasonable. > > Unfortunately I had someone complain at me that my mail servers kept > going to their secondary MX, turns out it was because he had a forced 2 > minute delay before responding to HELO and my mail server wasn't waiting > around that long. He had it because some website (the mailer was exim, > iirc) was advocating it and encouraging people to do it for all incoming > connections. That is just stupid, and he probably shouldn't be bothering to try and run a mail server, much less complain that people are hitting his secondary. There are other good reasons for introducing delays, and they are effective, but the above idea is just retarded. > The problem is that some people *are* silly, or stupid, > and schemes like this often end up misused, misconfigured, and > implemented wrong. That's why I don't like them. I can't disagree there. I guess what I'm trying to say is, I understand your misgivings, beause people implementing most anything can manage to do it in a really stupid, painful and harmful way. That doesn't necessarily mean the idea is unsound. Greylisting is, itself, a one-trick pony. It will lose it's effectiveness whenever spammers get around to implementing queues on their zombie clients. OTOH, admin'ing an MTA these days is an arm