Any actual good tutorials out there on how to setup SMTP auth?

[Red Squirrel]

I always try to do this then give up because the documentation is so poor and does not explain anything and I can never get it to work.

My new internet service seems to block outgoing port 25, so this broke my email. I can't send any email anymore. I obviously can't change the port on the server because now other mail servers wont be able to connect to it as it uses 25 by default when delivering. So I'm thinking of just adding TLS authentication, and it's probably the best way of going anyway so I don't have an open relay and manage what IPs can access it.

So how do I go about setting this up? I just went through a tutorial and copy and pasted a bunch of stuff, ran a bunch of openssl commands etc... but then it just left me hanging near the end. What's the username, what's the password? Who knows, because it did not even cover that.

I need a good tutorial that shows the whole thing. Is there anything out there? Anything I find was written in like 1995 and has not been updated since.

Worse case scenario I might just setup an "always on" VPN tunnel to the server and go about it that way but I kind of want to just do it properly and use TLS. Just can't seem to find any good tutorial that shows how to set it up step by step. Idealy, I'd like the username/password to be whatever is used for the pop account.

 

[bobross419]

If its Postfix you can pretty easily get around the ISP blocking port 25 by enabling submission (port 587) in /etc/postfix/master.cf. You can run this along side the regular port 25 SMTP. This is a pretty common fix and I'm sure you should be able to do this on other MTAs as well.

 

[Red Squirrel]

Thanks I was reading up on that and turns out I was able to just add this line in the master.cf:

26 inet n - n - - smtpd

Where 26 is the port number. This seems to have worked. That file is kind of missleading because all the other entries in there are the names of the port (ex: smtp instead of 25) so did not even know what any of those entries meant.

One of these days I should really sit down and figure out how to do proper authentication though. I'd probably end up having to look at the source and analyze and learn it.