On Mar 5, 2010, at 4:33 PM, Zachary Frederick wrote: > We have been having a problem emailing to a customer whose server is hosted > by The Planet (http://www.theplanet.com/). Our mail server is hosted in-house > on a comcast business connection. > > IP address of our server is: 173.13.45.23 > > Customers mail server is: 69.93.203.243 > > I cannot telnet to port 25 on their server, and they cannot telnet to port 25 > on ours. > > If I try to connect to their mail server from a different network such as my > home internet connection, I can connect. > We do not do any firewalling that would block this in anyway. We were able to > send and receive email to them when we used Qwest for our connection, before > we switched to Comcast. > > Comcast has said the problem is not on their end because it times out at The > Planet. > The Planet doesn't have much interest in speaking with me, because I'm not > their customer. > > Not sure what to do at this point. > > Below is a traceroute:
If you have a suitable platform, try tcptraceroute and see where port 25 is blocked.
