I recently performed an Exchange 2007 upgrade for a client who was moving from Exchange 2003. As part of their compliance with some regulations they are required to journal the activity of certain mailboxes within their organization. Journaling in this situation was enabled on the database level so all users in the database will have all emails sent and received forwarded to an external 3rd party mail server. This was done through a send connector to the 3rd party’s domain.
The problem the client was experiencing in Exchange 2007 was that all outbound emails originating internally were being sent to the external journaling provider however, all inbound emails were not being forwarded to the journaling provider.
The client contacted the Journaling provider and from a conversation it was determined that when an inbound message arrived to the Exchange Mailbox Server, it would be forwarded to the journaling provider from the original sender, the original sender being someone from outside the organization. This immediately put up a red flag in my head. I started to think, Exchange receives an email to send to a 3rd party, from a person outside of this trusted organization. Exchange was refusing to send the message! So, the thought came into play, how to configure this thing to allow it to relay to the 3rd party email server. Anyone? Anyone? Ok, the solution was actually quite simple and once I understood what was happening it was easy to figure out. I simply setup an Internal Relay! Yup, that’s it. The Internal Relay will allow Exchange 2007 to receive emails for a specific domain, query Active Directory for the mailbox and deliver the mail for that domain if it is found internally. If the mailbox is not found internally Exchange will then Relay the email for the 3rd party mailbox server specified in the Send connector which was already configured above! Walla, problem solved!
For more information on what an Internal Relay Domain is click here.
Have a great day!