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: traceroute to 69.93.203.243 (69.93.203.243), 64 hops max, 52 byte packets 1 223.254.254.75 (223.254.254.75) 2.610 ms 2.057 ms 2.033 ms 2 173-13-45-30-pennsylvania.hfc.comcastbusiness.net (173.13.45.30) 3.656 ms 2.997 ms 3.119 ms 3 * * * 4 68.85.72.129 (68.85.72.129) 10.497 ms 9.624 ms 12.245 ms 5 te-9-1-ur02.greensburg.pa.pitt.comcast.net (68.86.100.53) 9.935 ms 10.049 ms 10.505 ms 6 te-3-2-ar01.mckeesport.pa.pitt.comcast.net (68.86.100.49) 14.795 ms 12.846 ms 14.006 ms 7 te-0-4-0-5-cr01.mclean.va.ibone.comcast.net (68.86.91.129) 17.868 ms 16.278 ms 21.110 ms 8 pos-1-10-0-0-cr01.atlanta.ga.ibone.comcast.net (68.86.86.126) 43.022 ms 40.690 ms 39.818 ms 9 pos-1-15-0-0-cr01.dallas.tx.ibone.comcast.net (68.86.85.149) 58.980 ms 58.914 ms 59.673 ms 10 pos-0-0-0-0-pe01.1950stemmons.tx.ibone.comcast.net (68.86.86.90) 59.608 ms 60.322 ms 59.691 ms 11 theplanet-cr01.dallas.tx.ibone.comcast.net (75.149.228.2) 62.246 ms 61.320 ms 61.693 ms 12 te3-5.dsr01.dllstx3.theplanet.com (70.87.253.86) 61.431 ms te7-1.dsr02.dllstx3.theplanet.com (70.87.253.18) 58.859 ms 59.365 ms 13 76.fd.5746.static.theplanet.com (70.87.253.118) 62.690 ms te1-3.dsr02.dllstx2.theplanet.com (70.87.253.122) 68.123 ms te3-3.dsr02.dllstx2.theplanet.com (70.87.253.126) 59.382 ms 14 po1.car02.dllstx2.theplanet.com (70.87.254.82) 59.321 ms 60.268 ms 66.206 ms 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * * 31 * * * 32 * * * 33 * * * 34 * * * 35 * *^C