Cannot Receive External Mail

dps

Since this morning, we are not able to receive external e-mail. Sending and receiving internally is ok. Sending outside e-mail is fine too. We didn't change any settings whatsoever and I'm stumped on what else to check. I restarted our Exchange server but the problem's still there.

Hope you can give any ideas on what to do. We are running Exhange 2007 on a Win2k3 machine.
Not really an Exchange guru so please bear with me.

Thanks a lot.

iowatech

Do you know of anyone playing around with your MX records lately?

paintb4707

Oh my, bad memories.

Check the firewall, make sure its permitting incoming SMTP traffic to the Exchange server. That and if you're using a KVM, make SURE the IP is correct! :P

Netstudent

Contact your provider about DNS issues. This is pretty common. get on dnsstuff.com and see if you can get any free report info on your domain name. use the CLI to make your provider's DNS servers your default server via nslookup on your domain name to make sure it is correct or query the DNS server for it;s MX records.

Can you telnet to your external IP for email on port 25 or 110?

blargoe

Go to www.dnsreport.com and do an email test, and copy down the results.

Check the firewall (telnet to pt 25 from the Internet is a good suggestion)

Check the server: Make sure SMTP services are running. Make sure the C drive (or wherever the SMTP queue is located) is not full. Look at the ESM Queues, and make sure the mail isn't queued up on the server itself (then you have an Exchange problem instead of a network problem)

Check any other external factors. Does your ISP or anyone else do anything with your mail like filtering, or does the mail get sent directly to your Exchange server?

Make sure no one changed DNS records.

dps

For some strange reason, the mail-virus scanner in our Linux Server is queueing up incoming traffic. We're using Amavis and Postfix here and when we restarted the service, all queued up mail came in.

Thanks for all your help.