20 April 2017

Forward email to external domain - Exchange 2013 & Exchange 2016

By default email forwarding to an external domain is disabled on an out of the box Exchange 2013/2016 installation.
There are a lot of  blogs/threads/comments on the web that say to create a transport rule or to create a contact. Both of these will not work because autoforward to external domains is disabled (see below)

If you look in the message tracking logs you will find the following line:

To be able to do this for a specific domain only you can do the following:

Check your current settings:
Name                           DomainName                                   AllowedOOFType
----                           ----------                                   --------------
Default                        *                                            External

Check the auto forward settings:
Get-RemoteDomain | fl autofor*
AutoForwardEnabled : False

Add a new remote domain to allow forwarding to:
New-RemoteDomain -Name description -DomainName yourremotedomain.com

Check the auto forward settings for the new domain:
Get-RemoteDomain -Identity yourremotedomain | FL auto*            
AutoReplyEnabled   : True                        
AutoForwardEnabled : True

After doing all this you can create a rule in Outlook or OWA to forward an email to this particular domain only.