[TriLUG] location-specific SMTP problem

[Aaron Thomas]

Hello,


On Mon, 2014-07-21 at 15:11 -0400, Bill Farrow wrote:
> It is most likely AT&T blocking port 25 to prevent SPAM.
> 
> Could you enable the SMTP server to listen on another port as well as
> 25 and get your co-worker to use the new port number instead.


My bet is that on the co-workers route AT&T is blocking connections to
the IP Address your server is listening on. 

They seem to block first and ask questions later after a lot of pain in
getting them to respond. 

I would start with an MTR to your smtp server from the co-workers home.

mtr  --report <ip address of smtp server> --report-cycles=100


Hope this helps!