port 25 send mail problem

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#1 Thu, 01/10/2013 - 01:19
AllanIT

port 25 send mail problem

Hi

I am having a bit of a mail problem. I have a user who can connect to the server to receive mail but not send mail through Outlook. The problem is their isp does not allow port 25 for sending email. I need to add an additional port for sending email. Can you please tell me where I would add the additional port.

Thu, 01/10/2013 - 08:50
andreychek

Howdy,

I forget which off the top of my head, but either port 465 or 587 should be enabled by default.

You should be able to point Outlook at that port, tell it to use a secure connection, and it should then be able to send mail. Just have Outlook try both ports, one of those two should work :-)

If that doesn't work, the place to look is in /etc/postfix/master.cf. You'd want to enable both SMTPS and Submission. Also, you may want to go into Virtualmin, find a domain with SSL enabled, and go into Server Configuration -> Manage SSL Certs, and then have it copy the SSL cert into Postfix.

-Eric

Thu, 01/10/2013 - 12:46
AllanIT

Hi Eric

Their isp has 465 blocked also. I see in another post that some one used 5525 I was wondering if that would work in this case?

Sat, 01/12/2013 - 08:10
Locutus

465 is SMTPS, 587 is "submission", a port specifically for delivering outbound mail by local clients, as opposed to external servers sending in mail for local clients.

My suggestion would be to use any port that is not blocked; if you configure that in both Postfix and tell your user to use it, that should work fine. Another suggestion would be to kick that ISP's butt, because it makes absolutely no sense to block port 465 and 587 outgoing. Those ports cannot be used to send out spam or viruses (or whatever the reason for blocking port 25 is), since they're used only by local and authenticated clients.

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