Hello,
in 9.200-11 SMTP static SMTP routing conflicts in the following case with external (non local) domains.
Email Protection -> SMTP -> Routing : yourdomain.com is routed to static host list e.g. 10.10.10.25
Everiything works fine with this configuration, mail ist delivered as expexted to the internal mail server 10.10.10.25
Outgoing email from 10.10.10.25 is also relayed over the UTM. This also works as expected, but for the following case:
If you send mail from 10.10.10.25 to e.g. to yourdomain.com.au or yourdomain.com.in, then also the static host list seams to match and the UTM tries to deliver the mail back to 10.10.10.25, which of course results in a NDR.