[MTA-Mode] Internal mails from own domain dont get routed to smarthost but to internal exchange where they come from(Loop?)

Question

Hello Sophos Community, 
 we have an Exchange 2019 server with one domain(mydomain.de). 
 Some Mailboxes are NOT internal so I created them as contacts. Exchange now sends to mails to the XG Firewall that works in MTA Mode. 
 The XG sees the recipient is the same domain as my internal and routes the mail back to the Exchange server(Which creates a loop, see screenshot). 
 How can I change that for specific email adresses(not domains!)? I want the mails to be routed to the smarthost like every other mail. 
 
 Thanks!

FormerMember · Accepted Answer

Hi Philipp Greindl 
 Smarthost configuration on XG firewall is global, it can be used to redirect outbound emails through specific email server. 
 Are you trying to redirect outbound emails through Smarthost if they appear to be coming from specific email addresses only and not all? 
 If yes, it is not possible to change routing based on email addresses. 
 Thanks,