Exchange 2013 and getting FMS to relay to external addresses

[psydii]

It turns out that if you try to do it *and* authenticate FMS to the Exchange server, it is not straightforward. In fact one hits a kink in the road: undocumented mail flow changes in Exchange 2013...

 

Scenario: you have some applications / devices that need to relay to external addresses through your server. You want to implement *best practice* and have each application/device authenticate with its own AD account.

Problem: You get a 550 5.7.1 Client does not have permissions to send as this sender error.

Cycling through all the various authentication options you may also see 535 5.7.3 or 530 5.7.1

 

Here is the solution (as discovered by an Exchange MCM no less!)

 

 

http://geekswithblogs.net/ksellenrode/archive/2014/05/03/156170.aspx