Thanks for the fast answer. I would like to check the recipient-domain for our outgoing mails - should it not be something like this:

Condition: Envelope Recipient
Rule: rcpt-to == "@destination.com$"

Action: Send to Alternate Destination Host
Rule: alt-mailhost ("destination.host.com")
or
Rule: alt-mailhost ("[111.222.133.244]")

Outch, I apologize ! My brains were somehow cross-wired. You are absolutely right that the recipient address should be checked.

No problem - your idea was important!
Do you know, if my syntax for the IP-address for the alt-mailhost-address is correct? I'm not sure, if we can include it in our DNS...

Yep, the syntax is correct. Should work just as you describe

It seems like this could easily be handled with an SMTP Route since the destination domain is what you are trying to match on.


Its under the Network Tab in the GUI, or just "smtproutes" in the CLI.

You can set it up in the GUI like this:
Network -> SMTP Routes -> Add Route

Recieving Domain=boughtcompany.com
Destination Host=IP or hostname

You can also match on subdomains for the recieving domain if you use ".boughtcompany.com"

That should use up less CPU than a content filter.