US Telco Support > AT&T > AT&T Southeast > SMTP Server Problem

SMTP Server Problem

Based on your information, your son-in-law will probably need to create two profiles, one for working from his office, and one when working from home.

If he is actually trying to send email on port 25 using an AT&T email server from home, that should not be a problem since AT&T does not actually block outgoing port 25, they only filter it so that it can only be used for an AT&T email server.

I can use port 25 to send email using both mail.bellsouth.net and smtp.att.yahoo.com with no problems from my AT&T DSL circuits.

webhost:/ # telnet mail.bellsouth.net 25
Trying 204.127.217.17...
Connected to mail.bellsouth.net.
Escape character is '^]'.
220 isp.att.net - Maillennium ESMTP/MULTIBOX frfwmhc06 #75
quit
221 isp.att.net
 
Connection closed by foreign host.
webhost:/ # telnet smtp.att.yahoo.com 25
Trying 68.142.198.11...
telnet: connect to address 68.142.198.11: No route to host
Trying 76.13.12.104...
telnet: connect to address 76.13.12.104: No route to host
Trying 98.138.31.74...
Connected to smtp.att.yahoo.com.
Escape character is '^]'.
220 smtp101.sbc.mail.ne1.yahoo.com ESMTP
quit
221 Service Closing transmission
Connection closed by foreign host.
 
 

webhost:/ # telnet smtp.nuvox.net 587
Trying 70.43.63.17...
Connected to smtp.nuvox.net.
Escape character is '^]'.
220 smtp03.atlngahp.sys.nuvox.net ESMTP Tue, 7 Dec 2010 23:38:46 -0500
quit
221 2.0.0 smtp03.atlngahp.sys.nuvox.net closing connection
Connection closed by foreign host
 
 

That information is all good and helpful, but now I understand the problem better.

The only port that he can send through at work is 25.

The only port that he cannot send through AT&T at home is 25.

His work SMTP server can be accessed through port 25 even if he is away from the office, so long as he authenticates. Since 25 is the only port blocked at home, his work SMTP server is not accessible.

The ideal solution appeared to be using one of the alternate AT&T SMTP servers on port 25 from work, but since he needs to send his work email, which is not an AT&T email address, the AT&T SMTP server rejects the email even if he authenticates with his Bellsouth username and password.

At this point, I'm stuck. Here are the only options I see:

1. Try to get port 26 opened on his work SMTP server. (Not likely)
2. Get him to change his ISP from AT&T to the cable company.
3. Use a proxy, like HotSpot Shield (not sure that's safe)
4. Setup a desktop computer at work and access remotely

Can you think of any other solution?

If he is using the smtp.nuvox.net server, he may be able to use it with port 587 from his AT&T connection at home. See my previous post for my test results. Typically when an email server does not accept off-net traffic, they simply do not respond to off-net traffic. The fact that smtp.nuvox.net responds to the mail submission port 587 should indicate that they will accept mail from a properly authenticated user.

If he is not using smtp.nuvox.net as the smtp server, find out exactly what he is using and perhaps someone will actually be able to do something besides making guesses.

FYI, you can use foreign return addresses with smtp.att.yahoo.net, but you have to go through their verification process (which is a PITA). I have never had a problem using a foreign address when sending mail through fmailhost.isp.att.net on SSL port 465. That may not help at work, but it should work at home. Just using mail.bellsouth.net on port 25 should work from home. I use that from my home office email server all the time (with return addresses from my own domains as well as the domains of several clients).
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

He could access smtp.nuvox.net on 25 and on 587, but he could not authenticate. He can authenticate on smtp.nuvox.net on port 25 from work. His work email address is not nuvox.net, but they are his provider. (His work has its own domain name, which is what he uses for sending.) When he connects to nuvox.net on port 25 from work, he can authenticate.

You have been very helpful. If you don't mind, I'll send you a PM with his work domain. I'm not going to post it here. I've tried every other port I can think of for his work domain. The only port that I can get to send off-network is 25.