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Simple Python script as SMTP server for outgoing e-mails?

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  Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-21 16:42 +0200
    Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-22 00:48 +1000
      Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-21 18:19 +0200
        Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-21 11:46 -0600
          Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-21 22:34 +0200
            Re: Simple Python script as SMTP server for outgoing e-mails? Ivan Shmakov <oneingray@gmail.com> - 2013-07-21 20:53 +0000
            Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-21 18:28 -0600
              Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-22 14:11 +0200
                Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-22 22:29 +1000
                  Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-22 14:38 +0200
                    Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-22 22:51 +1000
                    Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-22 08:08 -0600
                    Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-23 00:15 +1000
                      Re: Simple Python script as SMTP server for outgoing e-mails? Duncan Booth <duncan.booth@invalid.invalid> - 2013-07-23 08:06 +0000
                        Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-23 19:19 +1000
                          Re: Simple Python script as SMTP server for outgoing e-mails? Duncan Booth <duncan.booth@invalid.invalid> - 2013-07-23 10:06 +0000
                            Strange behaviour with os.linesep Vincent Vande Vyvre <vincent.vandevyvre@swing.be> - 2013-07-23 13:42 +0200
                              Re: Strange behaviour with os.linesep Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-23 15:25 +0000
                                Re: Strange behaviour with os.linesep Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-23 19:41 -0400
                                Re: Strange behaviour with os.linesep Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-23 19:51 -0400
                                Re: Strange behaviour with os.linesep Vincent Vande Vyvre <vincent.vandevyvre@swing.be> - 2013-07-24 09:02 +0200
                                Re: Strange behaviour with os.linesep Chris Angelico <rosuav@gmail.com> - 2013-07-24 17:39 +1000
                                Re: Strange behaviour with os.linesep Terry Reedy <tjreedy@udel.edu> - 2013-07-24 12:01 -0400
                            Re: Strange behaviour with os.linesep Jason Swails <jason.swails@gmail.com> - 2013-07-23 08:39 -0400
                            Re: Strange behaviour with os.linesep Vincent Vande Vyvre <vincent.vandevyvre@swing.be> - 2013-07-23 15:10 +0200
                            Re: Strange behaviour with os.linesep Vincent Vande Vyvre <vincent.vandevyvre@swing.be> - 2013-07-23 15:26 +0200
                            Re: Strange behaviour with os.linesep Jason Swails <jason.swails@gmail.com> - 2013-07-23 09:35 -0400
                            Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-24 07:37 +1000
                        Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-23 19:30 +1000
                        [OT] SPF - was Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-23 09:12 -0600
                        Re: [OT] SPF - was Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-24 07:47 +1000
                        non sequitur: [OT] SPF - was Re: Simple Python script as SMTP server for outgoing e-mails? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-23 19:59 -0400
                          Re: non sequitur: [OT] SPF - was Re: Simple Python script as SMTP server for outgoing e-mails? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-07-24 01:42 +0000
                        Re: Simple Python script as SMTP server for outgoing e-mails? Sanjay Arora <sanjay.k.arora@gmail.com> - 2013-08-05 18:43 +0530
                    Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-22 10:25 -0600
                    Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-23 02:32 +1000
                Re: Simple Python script as SMTP server for outgoing e-mails? "Eric S. Johansson" <esj@harvee.org> - 2013-07-22 08:54 -0400
                  Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-23 23:48 +0200
                Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-22 08:10 -0600
                  Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-23 23:50 +0200
    Re: Simple Python script as SMTP server for outgoing e-mails? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-07-21 12:39 -0400
    Re: Simple Python script as SMTP server for outgoing e-mails? Grant Edwards <invalid@invalid.invalid> - 2013-07-21 21:01 +0000
      Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-22 14:13 +0200
      Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-22 14:19 +0200
        Re: Simple Python script as SMTP server for outgoing e-mails? Grant Edwards <invalid@invalid.invalid> - 2013-07-22 14:10 +0000
        Re: Simple Python script as SMTP server for outgoing e-mails? Michael Torrie <torriem@gmail.com> - 2013-07-22 08:21 -0600
        Re: Simple Python script as SMTP server for outgoing e-mails? Chris Angelico <rosuav@gmail.com> - 2013-07-23 02:12 +1000
        Re: Simple Python script as SMTP server for outgoing e-mails? Nobody <nobody@nowhere.com> - 2013-07-22 21:32 +0100
    Re: Simple Python script as SMTP server for outgoing e-mails? Kevin Walzer <kw@codebykevin.com> - 2013-07-22 10:14 -0400
      Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-07-23 23:53 +0200
        Re: Simple Python script as SMTP server for outgoing e-mails? Kevin Walzer <kw@codebykevin.com> - 2013-07-24 10:38 -0400
          Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-08-01 16:15 +0200
            Re: Simple Python script as SMTP server for outgoing e-mails? Wayne Werner <wayne@waynewerner.com> - 2013-08-03 06:47 -0500
              Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-08-06 12:44 +0200
            Re: Simple Python script as SMTP server for outgoing e-mails? Kevin Walzer <kw@codebykevin.com> - 2013-08-03 21:41 -0400
              Re: Simple Python script as SMTP server for outgoing e-mails? Gilles <nospam@nospam.com> - 2013-08-06 12:45 +0200

Page 3 of 3 — ← Prev page 1 2 [3]

#51017

On Sun, 21 Jul 2013 16:42:50 +0200, Gilles <nospam@nospam.com> declaimed
the following:

>Hello
>
>	Every once in a while, my ISP's SMTP server refuses to send
>perfectly legit e-mails because it considers them as SPAM.
>
>So I'd like to install a dead-simple SMTP server on my XP computer
>just to act as SMTP backup server.
>All I'd need is to change the SMTP address in my e-mail client, and
>off they go. No need for anything else like user authentication or
>SPAM control.
>

	Many ISPs now block "pass through" SMTP -- especially original port 25
SMTP; only "their" server is permitted to connect to outside hosts.

	If all your destinations are using TLS with alternate ports, you might
be okay, but if the mail is being sent over port 25, it won't go anywhere.

	WinXP Pro supposedly contains an SMTP server as part of the "Internet
Information Services" (IIS6) suite (optional component activated via
control panel). Win7 Pro seems to have removed that (SMTP) component from
IIS7.

-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

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#51022

On 2013-07-21, Gilles <nospam@nospam.com> wrote:

> Every once in a while, my ISP's SMTP server refuses to send
> perfectly legit e-mails because it considers them as SPAM.
>
> So I'd like to install a dead-simple SMTP server on my XP computer
> just to act as SMTP backup server. All I'd need is to change the SMTP
> address in my e-mail client, and off they go. No need for anything
> else like user authentication or SPAM control.

Unless you've got a static IP address, a domain name, and a valid MX
record that will match up when they do a reverse DNS lookup, it's
pretty unlikely that you're going to have much luck running an SMTP
server.  Most other SMTP servers are probably going to ignore or
reject your attempts to transfer mail from your own SMTP server.

> Is there a no-brainer, ready-to-use solution in Python that I could
> use for this?

I'd recommend postfix or exim if I was going to try to do it, but I
think they're Unix-only.

-- 
Grant

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#51032

On Sun, 21 Jul 2013 21:01:09 +0000 (UTC), Grant Edwards
<invalid@invalid.invalid> wrote:

>Unless you've got a static IP address, a domain name, and a valid MX
>record that will match up when they do a reverse DNS lookup, it's
>pretty unlikely that you're going to have much luck running an SMTP
>server.  Most other SMTP servers are probably going to ignore or
>reject your attempts to transfer mail from your own SMTP server.

I had forgotten about this. I'll give a try, and see how it goes.

>I'd recommend postfix or exim if I was going to try to do it, but I
>think they're Unix-only.

Thanks for the tip. Looks like Exim is available on Windows through
Cygwin
http://blogostuffivelearnt.blogspot.fr/2012/07/smtp-mail-server-with-windows.html

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#51033

On Sun, 21 Jul 2013 21:01:09 +0000 (UTC), Grant Edwards
<invalid@invalid.invalid> wrote:
>Unless you've got a static IP address, a domain name, and a valid MX
>record that will match up when they do a reverse DNS lookup, it's
>pretty unlikely that you're going to have much luck running an SMTP
>server.  Most other SMTP servers are probably going to ignore or
>reject your attempts to transfer mail from your own SMTP server.

Incidently, how do ISP MTAs find whether the remote MTA is legit or
running on some regular user's computer?

1. Query Reverse DNS for IP
2. Find domain
3. Query DNS for MX
4. ?

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#51042

On 2013-07-22, Gilles <nospam@nospam.com> wrote:
> On Sun, 21 Jul 2013 21:01:09 +0000 (UTC), Grant Edwards
><invalid@invalid.invalid> wrote:
>>Unless you've got a static IP address, a domain name, and a valid MX
>>record that will match up when they do a reverse DNS lookup, it's
>>pretty unlikely that you're going to have much luck running an SMTP
>>server.  Most other SMTP servers are probably going to ignore or
>>reject your attempts to transfer mail from your own SMTP server.
>
> Incidently, how do ISP MTAs find whether the remote MTA is legit or
> running on some regular user's computer?
>
> 1. Query Reverse DNS for IP
> 2. Find domain
> 3. Query DNS for MX
> 4. ?

There are a variety of things they check.  They've got lists of IP
address blocks that they know are residential DSL/cable customers, and
sometimes they'll reject mail from those regardless of what you do.

Some will compare the reverse-DNS lookup with the headers to make sure
you're being honest about things like return-path, some will compare
the IP address with the MX record for the domain they got when they
did the reverse-lookup-DNS, and they've all probably got a variety of
other secret heuristics they use to generate a "SPAM" score.

For many years I ran my own SMTP server and had it configured to
deliver mail directly to recipients.  About 10 years, I had to give up
on that because so many SMTP servers were rejecting/ignoring mail I
sent.  And I did have a static IP with a valid domain and MX record.

But it was a residential DSL IP address, and I suspect that was enough
to get mail rejected by some servers.

-- 
Grant Edwards               grant.b.edwards        Yow! Well, O.K.
                                  at               I'll compromise with my
                              gmail.com            principles because of
                                                   EXISTENTIAL DESPAIR!

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#51046

On 07/22/2013 06:19 AM, Gilles wrote:
> On Sun, 21 Jul 2013 21:01:09 +0000 (UTC), Grant Edwards
> <invalid@invalid.invalid> wrote:
>> Unless you've got a static IP address, a domain name, and a valid MX
>> record that will match up when they do a reverse DNS lookup, it's
>> pretty unlikely that you're going to have much luck running an SMTP
>> server.  Most other SMTP servers are probably going to ignore or
>> reject your attempts to transfer mail from your own SMTP server.
> 
> Incidently, how do ISP MTAs find whether the remote MTA is legit or
> running on some regular user's computer?
> 
> 1. Query Reverse DNS for IP
> 2. Find domain
> 3. Query DNS for MX
> 4. ?

My mail server did a number of things:
1. ensure IP address of sending server has a reverse name (domain didn't
particularly matter)
2. ensure the HELO address in SMTP matches IP address of sending server
3. check sender IP address against spam blacklists, which includes
netblocks of home ISPs, some entire countries, flagged subnets
4. greylist sender IP if the recipient requested it.  First connection
always fails with a nonfatal server error, next connection must wait at
least 5 minutes.  If a reconnection happened too quickly, the IP was
temporarily black listed.  After success, IP address is whitelisted for
a time.  A commandline MTA will not be able to get through greylisting;
only a mail server with queuing could.  Spambots tend to give up on the
first error, even now. Cheaper targets I guess.
5. spamassassin checked SPF (DNS) and domainkeys (message itself) and
weighted the spam factor accordingly

I think there were other basic rules that sendmail applied to the
sender, but I can't remember all of what they are.  This is well and
truly off topic now for the python list, though.

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#51050

On Tue, Jul 23, 2013 at 12:21 AM, Michael Torrie <torriem@gmail.com> wrote:
> My mail server did a number of things:
> 1. ensure IP address of sending server has a reverse name (domain didn't
> particularly matter)
> 2. ensure the HELO address in SMTP matches IP address of sending server
> 3. check sender IP address against spam blacklists, which includes
> netblocks of home ISPs, some entire countries, flagged subnets
> 4. greylist sender IP if the recipient requested it.  First connection
> always fails with a nonfatal server error, next connection must wait at
> least 5 minutes.  If a reconnection happened too quickly, the IP was
> temporarily black listed.  After success, IP address is whitelisted for
> a time.  A commandline MTA will not be able to get through greylisting;
> only a mail server with queuing could.  Spambots tend to give up on the
> first error, even now. Cheaper targets I guess.
> 5. spamassassin checked SPF (DNS) and domainkeys (message itself) and
> weighted the spam factor accordingly
>
> I think there were other basic rules that sendmail applied to the
> sender, but I can't remember all of what they are.  This is well and
> truly off topic now for the python list, though.

And yet off-topic does happen... For what it's worth, here's how my
server is set up:
1. A variety of protocol-level checks. If you don't say HELO, for
instance, you get rejected. Surprisingly, these simple checks actually
keep out a lot of spam - but I've yet to see any legiit mail blocked
by them. (Not that I keep logs of these any more. I stopped watching
after it looked clean for a while.) And if legit mail is rejected,
it'll be resent or bounced by the sending MTA anyway.
2. SPF checks on the MAIL FROM:<> address. Again, if legit mail gets
rejected (which would be the fault of the sending domain owner), the
server at the previous hop will deal with it. Only hard failures get
thrown out; anything else just gets marked (which we usually ignore)
and delivered as normal, not even spam-scored.
3. Bayesian spam filter, set very conservatively so we get false
negatives but (almost) no false positives.

Any spam that gets through these three checks gets delivered, and then
the users will drop it in their junk folder. Every week I do a
train-and-wipe run across all junk folders, which logs spam counts
from our primary mailboxes. Last week's run was 228 spam across the
six logged accounts (some of those accounts collect from many
addresses), or an average of five false negatives per account per day,
and false positives are almost completely unheard-of. Considering how
much spam assaults the outside of my fortress's walls, that's a fairly
good ratio, I think. SPF for the win.

ChrisA

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#51059

On Mon, 22 Jul 2013 14:19:57 +0200, Gilles wrote:

> Incidently, how do ISP MTAs find whether the remote MTA is legit or
> running on some regular user's computer?

Look up the IP address in a database. If they don't have a database,
perform a reverse DNS lookup and reject anything which looks like a
typical auto-generated name for a consumer DSL/cable connection.

FWIW, I've been running sendmail on my home system (ADSL with static IP)
for years, and have had very few problems with mail being rejected.

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#51044

On 7/21/13 10:42 AM, Gilles wrote:
> Hello
>
> 	Every once in a while, my ISP's SMTP server refuses to send
> perfectly legit e-mails because it considers them as SPAM.
>
> So I'd like to install a dead-simple SMTP server on my XP computer
> just to act as SMTP backup server.
> All I'd need is to change the SMTP address in my e-mail client, and
> off they go. No need for anything else like user authentication or
> SPAM control.
>
> Is there a no-brainer, ready-to-use solution in Python that I could
> use for this?
>
> Thank you.
>

http://www.hmailserver.com

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com

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#51104

On Mon, 22 Jul 2013 10:14:15 -0400, Kevin Walzer <kw@codebykevin.com>
wrote:
>http://www.hmailserver.com

Thanks. hMailServer was one of the apps I checked, and I was just
making sure there weren't something simpler, considering my needs,
ideally something like Mongoose MTA.

Regardless, because of the SPAM anti-measures mentioned above, it
seems like I was over-optimistic about running an MTA and sending
e-mails from my home computer :-/

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#51136

On 7/23/13 5:53 PM, Gilles wrote:
> On Mon, 22 Jul 2013 10:14:15 -0400, Kevin Walzer <kw@codebykevin.com>
> wrote:
>> http://www.hmailserver.com
>
> Thanks. hMailServer was one of the apps I checked, and I was just
> making sure there weren't something simpler, considering my needs,
> ideally something like Mongoose MTA.
>
> Regardless, because of the SPAM anti-measures mentioned above, it
> seems like I was over-optimistic about running an MTA and sending
> e-mails from my home computer :-/
>

The reason I mentioned hMailServer is that I host my own mail server for 
my business--I have a static IP address, and correctly configured 
DNS--and so I'm able to send out large batches of e-mails to customers 
from my network without being blocked by my ISP. I'm running a Mac 
server so my mail system is the typical Unix setup (Postfix, etc.), but 
hMailServer was the closest thing I've found for Windows.

Configuring your own server isn't cheap in terms of time even if you use 
FOSS components, and your ISP may charge more for a static IP, so I 
completely understand if you don't want to go that route.

--Kevin

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com

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#51734

On Wed, 24 Jul 2013 10:38:52 -0400, Kevin Walzer <kw@codebykevin.com>
wrote:
>> Thanks. hMailServer was one of the apps I checked, and I was just
>> making sure there weren't something simpler, considering my needs,
>> ideally something like Mongoose MTA.
>>
>> Regardless, because of the SPAM anti-measures mentioned above, it
>> seems like I was over-optimistic about running an MTA and sending
>> e-mails from my home computer :-/
>>
>
>The reason I mentioned hMailServer is that I host my own mail server for 
>my business--I have a static IP address, and correctly configured 
>DNS--and so I'm able to send out large batches of e-mails to customers 
>from my network without being blocked by my ISP. I'm running a Mac 
>server so my mail system is the typical Unix setup (Postfix, etc.), but 
>hMailServer was the closest thing I've found for Windows.
>
>Configuring your own server isn't cheap in terms of time even if you use 
>FOSS components, and your ISP may charge more for a static IP, so I 
>completely understand if you don't want to go that route.

Thanks for the infos. Indeed, it seems like hMailServer is one of the
few good MTAs for Windows.

I already have a static IP, so the issue is more that remote MTAs
might not accept connections from MTAs running on users' PC instead of
ISP's.

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#51854

On Thu, 1 Aug 2013, Gilles wrote:

> On Wed, 24 Jul 2013 10:38:52 -0400, Kevin Walzer <kw@codebykevin.com>
> wrote:
>>> Thanks. hMailServer was one of the apps I checked, and I was just
>>> making sure there weren't something simpler, considering my needs,
>>> ideally something like Mongoose MTA.

Have you checked Kenneth Rietz's inbox.py[1]? It's fairly simple to 
use/extend and might fit your modest needs.


-W

[1]:https://crate.io/packages/inbox/

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#52026

On Sat, 3 Aug 2013 06:47:07 -0500 (CDT), Wayne Werner
<wayne@waynewerner.com> wrote:
>Have you checked Kenneth Rietz's inbox.py[1]? It's fairly simple to 
>use/extend and might fit your modest needs.
>
>
>-W
>
>[1]:https://crate.io/packages/inbox/

Thanks. I'll check it out.

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#51911

On 8/1/13 10:15 AM, Gilles wrote:
> I already have a static IP, so the issue is more that remote MTAs
> might not accept connections from MTAs running on users' PC instead of
> ISP's.

For what it's worth, that hasn't been my experience.

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com

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#52027

On Sat, 03 Aug 2013 21:41:16 -0400, Kevin Walzer <kw@codebykevin.com>
wrote:
>For what it's worth, that hasn't been my experience.

Thanks for the feedback. I'll experiment and see how it goes.

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