Hi All, I can send and receive internal and external emails, but cannot receive external emails. My DNS is resolving, the MX record looks good, POP3 and SMTP connectors have been configured, mailboxes are fine too. Port 25 and 110 are both being forwarded to the exchange server as well. I'm not using an ISP for emails. The domain nameserver is with Network Solutions and I've had them create the MX record which points to the A record which finally points to the firewall/router. Any ideas?

Hi Selims - I'll start with the obvious ... Is the firewall/router accepting SMTP traffic? If so, are you routing SMTP from the outside to inside properly? Are you using a Edge Transport server in a DMZ? (not required but curious) - Matt

First question: What version of Exchange Server? If this is Exchange Server 2007 make sure you have Anonymous Users checked under the Permissions tab of the Default Receive Connectors properties. Server Configuration - Hub Transport - Default Receive Connector By default the Hub Transport role will not receive outside email. That is the current setup I am using as we do not have an Edge Transport Server.

Try Reverse DNS - goto dnsstuff.com and check your reverseDNS, your ISP should have a reverseDNS record for your mail server.