Servers are Exchange 2003 SP2 and are Front/back configuration.
The Front end is on a DMZ and where our MX record points.
Message filtering is enabled on the Front end SMTP Virtual Server, but not the back-end Virtual SMTP. Once I check “Filter recipients who are not in the Directory” and restart SMTP all outgoing messages from my Back-end server get an undeliverable 550 error message.
No message to an outbound email succeeds until I Uncheck the box and restart the SMTP server on the front-end. An example text is below.
“The following recipient(s) cannot be reached:
< Backendserver #5.7.1 smtp;550 5.7.1 You do not have permission to send to this recipient. For assistance, contact your system administrator.>”
I’ve never dealt with a front/back configuration and it seems like the Front wouldn’t check for recipients when the Back is sending it.
Any insight would be appreciated. I’m guessing I’m overlooking the obvious but searches on the Web resolve few situations with Front/Back and Recipient filtering trouble shooting.