SMTP-Submit & Zimbra

[tbridge]

Lately I've found myself in places where SMTP outbound traffic is blocked to my access. I spend some quality time on public internet access (think coffeeshop) and I'm wondering if there's a way that Zimbra can accept SMTP-Submit traffic on a non-25 port (I think standard for EIMS and the like is 587?).

Has anyone modded Zimbra's OS Edition to do this?

[KevinH]

You could add a rule to iptables to map a non-25 port to 25 for this purpose.

[bobby]

courtesy of marcmac:
------------------------
On the mta server, as root:
edit /opt/zimbra/postfix/conf/master.cf

Look for this line near the top:
smtp inet n - n - - smtpd

Immediately below that, add the line
26 inet n - n - - smtpd

Once that's done:
su - zimbra
postfix reload

You'll need that on every MTA, and this will NOT persist across upgrades (you'll need to repeat this procedure).
------------------------

[tbridge]

Where 26 is the new and different portnumber?

Originally Posted by bobby

courtesy of marcmac:
------------------------
On the mta server, as root:
edit /opt/zimbra/postfix/conf/master.cf

Look for this line near the top:
smtp inet n - n - - smtpd

Immediately below that, add the line
26 inet n - n - - smtpd

Once that's done:
su - zimbra
postfix reload

You'll need that on every MTA, and this will NOT persist across upgrades (you'll need to repeat this procedure).
------------------------

[bobby]

exactly. should have mentioned that

[tbridge]

Now, the $64,000 question...

Can I use the new 587 port as a mail relay for other domains?

[KevinH]

That should work if you configure those domains to transport to some other mta.

More info on that here:

http://wiki.zimbra.com/index.php?title=ManagingDomains

[tbridge]

Ah, I misspoke.

Another mailserver I am familiar with, EIMS, when SMTP-Submit is enabled, so long as you authenticate to EIMS as a user on the server, you may send mail from any domain through EIMS. This does not seem to be the case with Zimbra, and I'm assuming that's intentional...

Is there a way around that?

[KevinH]

Originally Posted by tbridge

Is there a way around that?

Not sure off hand other than listing all the domains. I think you should be able to config Postfix to allow you to fully relay mail for all auth'd users.

[jonnyRo]

Originally Posted by bobby

courtesy of marcmac:
------------------------
On the mta server, as root:
edit /opt/zimbra/postfix/conf/master.cf

Look for this line near the top:
smtp inet n - n - - smtpd

Immediately below that, add the line
26 inet n - n - - smtpd

Once that's done:
su - zimbra
postfix reload

You'll need that on every MTA, and this will NOT persist across upgrades (you'll need to repeat this procedure).
------------------------

What does the line starting with 26 do?