At about 9:00 this morning I began to receive word that e-mail messages from district accounts were being rejected by Google/Gmail and a few other sites. I investigated these reports and confirmed that messages were being rejected. The problem that Google reported was that the IP address of our outgoing mail servers were not resolvable externally. This is a standard check to keep spam from flooding their system. I contacted SCOE and they added external DNS entries so Google and other sites could perform reverse lookups on our SMTP servers' IP addresses. After the entries were created, I sent test messages to Gmail and confirmed delivery.
This behavior was caused by a Routing Connector that was created by Exchange 2010 when a Hub Transport server was introduced into our Exchange organization. Exchange 2010 forced our Exchange 2003 system to route all outgoing mail through one of the new Exchange Hub Transport servers that was not prepared for deployment. Luckily it was not difficult to identify or fix.
