After some years I’m refreshing my knowledge with Exchange.
The base setup of Exchange was done fast and the external access over NetScaler was easy with a script of a colleague.
But now, I wanted to serve an internal SMTP relay server of some internal services.
I found some good explanations on the site of Paul Cunningham (Link).
But unfortunately it doesn’t work within the Web GUI. The reason was like in other things a bug from Microsoft and the solution was found in Powershell. I found a manual by Jeff Guillet (Link).
The SMTP Relay was working if i configure the connections directly to the Exchange server but not through the NetScaler. And I wanted to solve this issue: