[Mailman-Users] email bouncing back to sender...(part deux)...

[Nathan K. Stazewski]

OK, yesterday I asked about why our mailman client wasn't accepting emails.
The problem was that the physical computer had been moved, so it had
attained a new IP and port 25 was being blocked at that IP by our firewall.
Our IT has since changed the directing, and it seems that everything is
directing to the new IP and the port can now be telnetted to, so I figure
that must be working.  What else needs to be changed though?  Right
afterward these changes had been made, I was able to send emails from on our
campus and they went through.  Then I tried to send from AOL.went
through.tried from hotmail and another college's server.neither shows up and
they're not pending.  After sending about 15 test emails.all emails stopped
coming through.no matter where I send them from.  Is there anything on the
Mac that I need to change since the IP is different?  I was told that I
needed an MX record published, and I have never even heard of this.  I
googled it and got the gist of it.but haven't a clue if I still need to do
that after other stuff was fixed.  I apologize for my ignorance.but this is
being run from a Mac and the only person that had anything to do with this
listserv no longer works here, so all I know is that it's a Mailman client
using postfix.

 

Again.the server in question is alumni-office.swarthmore.edu.  Thanks so
much in advance.