Outlook mail forwarding rule to external address not working

You might notice that, your Microsoft Exchange environment, if your users setup outlook rules to automatically forward their emails to an external email address, these rules will not work and the forwarded email will never leave your organization.

This is because Exchange blocks, by default,automatic forwarding message. To solve this problem you will need to follow the below steps

Exchange 2003

1. Open Exchange System Manager
2. Expand Global Settings
3. Locate Internet Message Formats
4. In the right-hand panel, right click Properties on "Default"
5. In the Advanced tab, check the option "Allow Automatic Forward"

Exchange 2007/2010
In Exchange 2007/2010 "Internet Message Formats" is replaced by "Remote Domains"

1. Open Exchange Management Console
2. Organization Configuration
3. Hub Transport
4. Remote Domains tab
5. Right click properties on Default
6. Message Format tab
7. Check "Allow automatic forward"

The same can be done using powershell by running

set-RemoteDomain * -AutoForwardEnabled:$true

About Antoine Khater

I have been working in IT consultancy and solution integration since 1998 and I consider myself lucky to be, one in a few, making a living out of my passion. I am also member of the famous Experts Exchange (profile here) online community where I try my best to share what I have learned along the road.