We have Exchange 5.5 SP4 - since ap

[deanderson]

We have Exchange 5.5 SP4 - since applying SP6a for Windows NT4.0, Exchange is unable to send any external e-mail, it can receive e-mail with no problems. It would appear that the problem is DNS name resolution as errors in Event Viewer point to the ISP host server not getting resolved. This is a Dial Up connection and even if I replace the ISP mail server name with an IP address, external mail still fails to be sent, I can also ping the ISP servers by IP address and name. The problem is not with the Dial Up connection because Internet browsing uses this and that still works. Proxy server 2.0 is also in the equation but I have tried with no packet filtering and still get the problem. I am now tending to think that the TCP/IP stack is corrupt and was going to remove and reinstall then re-add the Internet Mail Service.

Has anyone got any more ideas?

Your help would be greatly appreciated

Dean A.

 

[zoeythecat]

Not being a DNS expert, but I assume you have a DNS server and if so would you need to add an MX record or add a record here somewhere ro resolve external email? Somewhere something has changed.

Have you tried rebooting the Exchange Server?

Sorry for not being more help.