I started work for a new client today who have a Windows 2000 Advanced Server with ~10 machines running XP & Win98. There is no Exchange server installed, so each machine is essentially using e-mail locally. They are set up using Outlook Express and they use web.com to host their e-mail. They said to have not been able to send mail, only receive mail. I set their outgoing mail server to mail.optonline.net which allowed them to send mail but only temporarily. Within a few hours they were getting the following error:
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: 'pop.registeredsite.com', Server: 'mail.optonline.net', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 10053, Error Number: 0x800CCC0F
I tried to troubleshoot a bit and found that I couldn't telnet mail.optonline.net 25 from the server or any machines but I could telnet fine from my remote machine off the network. I rebooted the server and router(D-Link SOHO) and was then able to telnet fine and e-mail worked perfectly.
4 hours later I got a call saying that they were getting the same error and couldn't send mail. I logged into the server remotely and found that I was no longer able to telnet mail.optonline.net 25. I rebooted the server twice, and I still can't telnet in. Only thing different is I'm not able to reboot the router remotely.
Any ideas? They have Symantec Corporate installed. I can log in remotely all night but won't have physical access again until tomorrow.