Re: Question about smtplib, and mail servers in general.

2005-09-26 Thread Christos Georgiou
On Tue, 20 Sep 2005 16:48:41 +0200, rumours say that Piet van Oostrum
[EMAIL PROTECTED] might have written:

And most smtp servers that I know also pass mail from any from-address to
any to-address if the IP number of he client machine belongs to a trusted
range (usually the range that belongs to the ISP). So I can send both my
private mail and my work mail from both my home ISP's smtp server and my
work's smtp server (but only if I am at the proper location).

You might start having troubles, though, as soon as SPF checks get more
widespread.

Say your work mail is [EMAIL PROTECTED], and your private mail is
[EMAIL PROTECTED]; if you send email through your office mail server
with the envelope MAIL FROM: [EMAIL PROTECTED], then some (and
eventually many) receiving servers shall ask yagoohoogle.com for their
SPF record, and since your office mail server won't probably show up as
a valid email sender from yagoohoogle.com , your email will get
rejected.

That's a good thing.
-- 
TZOTZIOY, I speak England very best.
Dear Paul,
please stop spamming us.
The Corinthians
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-26 Thread Christos Georgiou
On Wed, 21 Sep 2005 07:50:26 +0100, rumours say that Steve Holden
[EMAIL PROTECTED] might have written:

I agree that there's an element of the moral imperative in my assertion 
that the mails should go through which is largely ignored by the real 
world nowadays. Some ISPs force you to use their SMTP servers no matter 
what the sending domain, which is rather annoying when you travel a lot. 
I end up having to vary my default SMTP server as I move.

...or set up your email client to always connect to localhost ports eg
31025 and 31110, and then from wherever you are, you connect to an SSH
server trusted by your standard mail server and port-forward to it.

Don't know if this applies to your case, but it works for me :)
-- 
Christos Georgiou, Customer Support Engineer
Silicon Solutions, Medicon Ltd.
Melitonos 5, Gerakas 153 44 Greece
Tel +30 21 06606195 Fax +30 21 06606599 Mob +30 693 6606195
Dave always exaggerated. --HAL
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-21 Thread Steve Holden
Peter Hansen wrote:
 Steve Holden wrote:
 
Peter Hansen wrote:

In any case, unless the mail server will allow relaying, which most 
don't these days (to prevent spamming), then it won't work the way you 
are hoping unless *all* the 100 addresses are local ones, to be 
delivered to users on the server you are sending the mail to.

If the addresses are scattered all over the planet, and the server 
allows relaying, then it's intended for exactly this sort of use 
(other than if it's spam ;-) ), and no, you won't be putting a drain 
on the server.

To add one final note, if the fromaddress belongs to a domain that's 
properly handled by the SMTP server then you aren't relaying (since you 
are a legitimate domain user) so the mails should go through.
 
 
 I think that statement might not be widely valid any more, Steve.  In my 
 experience, lately, many if not most servers pay no attention to the 
 MAIL FROM address but instead allow relaying only from *IP addresses* 
 on the internal network (e.g. those served by an ISP, for example), 
 regardless of how the sender is identified.  On a Linux box with Qmail, 
 for example, one would have an /etc/tcp.smtp file which specifies for 
 which subnets relaying is allowed, and all others are disallowed 
 regardless of the claimed MAIL FROM address.
 
 It's kind of a shame, really, that you can no longer trust either the 
 recipient *or* the sender addresses when using basic SMTP.  Damn spammers.
 
I agree that there's an element of the moral imperative in my assertion 
that the mails should go through which is largely ignored by the real 
world nowadays. Some ISPs force you to use their SMTP servers no matter 
what the sending domain, which is rather annoying when you travel a lot. 
I end up having to vary my default SMTP server as I move.

regards
  Steve
-- 
Steve Holden   +44 150 684 7255  +1 800 494 3119
Holden Web LLC www.holdenweb.com
PyCon TX 2006  www.pycon.org

-- 
http://mail.python.org/mailman/listinfo/python-list


Question about smtplib, and mail servers in general.

2005-09-20 Thread Chris Dewin
Hi. I've been thinking about using smtplib to run a mailing list from my 
website.

s = smtplib.SMTP(server)
s.sendmail(fromaddress, toaddresess, msg)

I know that in this instance, the toaddresses variable can be a variable
of type list.

Suppose the list contains well over 100 emails. Would that create some
sort of drain on the mail server? Would I be better off doing it in some
other way? 

-- 
www.wintergreen.in

-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Tim Williams (gmail)
On 20/09/05, Chris Dewin [EMAIL PROTECTED] wrote:
 
 s = smtplib.SMTP(server)
 s.sendmail(fromaddress, toaddresess, msg)
 
 I know that in this instance, the toaddresses variable can be a variable
 of type list.
 
 Suppose the list contains well over 100 emails. Would that create some
 sort of drain on the mail server? Would I be better off doing it in some
 other way?

 
 Suppose the list contains well over 100 emails

You mean the list of recipients (toaddresses) ?  

The 2 lines of example code send a *single* email to server with
len(toaddresses) recipients.  The server will then split the email
into smaller (or individual) email groups to send (depending on the
server in use and the mechanisms it uses to relay  the email)

You could send a single email for each recipient to server

 s = smtplib.SMTP(server)
for addr in toaddresses:
  s.sendmail(fromaddress,[addr], msg)
# in later revisions, [addr] can be a list,  or a string of one address

but that would create much more load on your machine AND server

HTH :)
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Daniel Dittmar
Chris Dewin wrote:
 Hi. I've been thinking about using smtplib to run a mailing list from my 
 website.
 
 s = smtplib.SMTP(server)
 s.sendmail(fromaddress, toaddresess, msg)
 
 I know that in this instance, the toaddresses variable can be a variable
 of type list.
 
 Suppose the list contains well over 100 emails. Would that create some
 sort of drain on the mail server? Would I be better off doing it in some
 other way? 
 

Not really an answer to your question, but it's probably considered bad 
style to publish the email addresses of the recipients via the address 
list. Use a neutral To-address (best: the mailing list address) and add 
the recipients via bcc: headers.

You might also want to look at mailman 
http://www.gnu.org/software/mailman/, which is a complete mailing list 
solution written in Python.

Daniel
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Tim Williams (gmail)
On 20/09/05, Daniel Dittmar [EMAIL PROTECTED] wrote:
 Chris Dewin wrote:
  Hi. I've been thinking about using smtplib to run a mailing list from my 
  website.
 
  s = smtplib.SMTP(server)
  s.sendmail(fromaddress, toaddresess, msg)

 
 
 Not really an answer to your question, but it's probably considered bad
 style to publish the email addresses of the recipients via the address
 list. Use a neutral To-address (best: the mailing list address) and add
 the recipients via bcc: headers.
 

For clarity

The toaddreses don't show in the email,  they are the envelope TO:
addreses.   The addresses in the email's TO: Headers are shown to the
recipient and these are the ones that should be disguised as best
practice for mailing lists.

The email module's replace_header('to', 'new-text) will do the job for you.
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Peter Hansen
Daniel Dittmar wrote:
 Chris Dewin wrote:
 
 Hi. I've been thinking about using smtplib to run a mailing list from 
 my website.

 s = smtplib.SMTP(server)
 s.sendmail(fromaddress, toaddresess, msg)

 I know that in this instance, the toaddresses variable can be a variable
 of type list.

 Suppose the list contains well over 100 emails. Would that create some
 sort of drain on the mail server? Would I be better off doing it in some
 other way?
 
 Not really an answer to your question, but it's probably considered bad 
 style to publish the email addresses of the recipients via the address 
 list. Use a neutral To-address (best: the mailing list address) and add 
 the recipients via bcc: headers.

Not only not an answer, but also not a valid point in this case.  The 
list of recipients used in the sendmail() call (which become RCPT TO: 
commands in SMTP) do *not* show up in the received emails.  Only those 
items explicitly listed in the headers, such as the To: header, will 
appear.  In fact, you could easily make a Bcc: header which actually 
lists everyone and it would probably not even be stripped by most mail 
programs (though I haven't tried that).  Your confusion is caused by not 
distinguishing between mail client programs and a lower level utility 
such as smtplib, which doesn't even look at the To: addresses in the header.

-Peter
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Peter Hansen
Chris Dewin wrote:
 Hi. I've been thinking about using smtplib to run a mailing list from my 
 website.
 
 s = smtplib.SMTP(server)
 s.sendmail(fromaddress, toaddresess, msg)
 
 I know that in this instance, the toaddresses variable can be a variable
 of type list.
 
 Suppose the list contains well over 100 emails. Would that create some
 sort of drain on the mail server? Would I be better off doing it in some
 other way? 

Definitely consider a proper mailing list program like Mailman, as 
Daniel suggested.

In any case, unless the mail server will allow relaying, which most 
don't these days (to prevent spamming), then it won't work the way you 
are hoping unless *all* the 100 addresses are local ones, to be 
delivered to users on the server you are sending the mail to.

If the addresses are scattered all over the planet, and the server 
allows relaying, then it's intended for exactly this sort of use (other 
than if it's spam ;-) ), and no, you won't be putting a drain on the 
server.

-Peter
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Steve Holden
Peter Hansen wrote:
 Chris Dewin wrote:
 
Hi. I've been thinking about using smtplib to run a mailing list from my 
website.

s = smtplib.SMTP(server)
s.sendmail(fromaddress, toaddresess, msg)

I know that in this instance, the toaddresses variable can be a variable
of type list.

Suppose the list contains well over 100 emails. Would that create some
sort of drain on the mail server? Would I be better off doing it in some
other way? 
 
 
 Definitely consider a proper mailing list program like Mailman, as 
 Daniel suggested.
 
 In any case, unless the mail server will allow relaying, which most 
 don't these days (to prevent spamming), then it won't work the way you 
 are hoping unless *all* the 100 addresses are local ones, to be 
 delivered to users on the server you are sending the mail to.
 
 If the addresses are scattered all over the planet, and the server 
 allows relaying, then it's intended for exactly this sort of use (other 
 than if it's spam ;-) ), and no, you won't be putting a drain on the 
 server.
 
 -Peter
To add one final note, if the fromaddress belongs to a domain that's 
properly handled by the SMTP server then you aren't relaying (since you 
are a legitimate domain user) so the mails should go through.

regards
  Steve
-- 
Steve Holden   +44 150 684 7255  +1 800 494 3119
Holden Web LLC www.holdenweb.com
PyCon TX 2006  www.pycon.org

-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Piet van Oostrum
 Steve Holden [EMAIL PROTECTED] (SH) wrote:

SH To add one final note, if the fromaddress belongs to a domain that's
SH properly handled by the SMTP server then you aren't relaying (since you are
SH a legitimate domain user) so the mails should go through.

And most smtp servers that I know also pass mail from any from-address to
any to-address if the IP number of he client machine belongs to a trusted
range (usually the range that belongs to the ISP). So I can send both my
private mail and my work mail from both my home ISP's smtp server and my
work's smtp server (but only if I am at the proper location).
-- 
Piet van Oostrum [EMAIL PROTECTED]
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4]
Private email: [EMAIL PROTECTED]
-- 
http://mail.python.org/mailman/listinfo/python-list


Re: Question about smtplib, and mail servers in general.

2005-09-20 Thread Peter Hansen
Steve Holden wrote:
 Peter Hansen wrote:
 In any case, unless the mail server will allow relaying, which most 
 don't these days (to prevent spamming), then it won't work the way you 
 are hoping unless *all* the 100 addresses are local ones, to be 
 delivered to users on the server you are sending the mail to.

 If the addresses are scattered all over the planet, and the server 
 allows relaying, then it's intended for exactly this sort of use 
 (other than if it's spam ;-) ), and no, you won't be putting a drain 
 on the server.
 
 To add one final note, if the fromaddress belongs to a domain that's 
 properly handled by the SMTP server then you aren't relaying (since you 
 are a legitimate domain user) so the mails should go through.

I think that statement might not be widely valid any more, Steve.  In my 
experience, lately, many if not most servers pay no attention to the 
MAIL FROM address but instead allow relaying only from *IP addresses* 
on the internal network (e.g. those served by an ISP, for example), 
regardless of how the sender is identified.  On a Linux box with Qmail, 
for example, one would have an /etc/tcp.smtp file which specifies for 
which subnets relaying is allowed, and all others are disallowed 
regardless of the claimed MAIL FROM address.

It's kind of a shame, really, that you can no longer trust either the 
recipient *or* the sender addresses when using basic SMTP.  Damn spammers.

-Peter
-- 
http://mail.python.org/mailman/listinfo/python-list