Use recipient address map while keeping a default route

Question

While migrating progressively to G Suite, a default route needs to be established: Any destination not corresponding to an account routed to a custom SMTP server (what used to be our previous MX settings).

In the second step, the "forwarding aliases" part of the old system is migrated. This implies using G Suite Recipient address map.

What we observed is that although email addresses are correctly rewritten by G Suite, it still attempt to deliver them using to the old MX system (default routing).

What we would expect is to deliver them "naturally" (MX DNS resolution on the rewritten address).

Is it possible to achieve this in G Suite?

Answer 1

I intended to solve the same scenario the same way. It did not work.

You can check Email Log Search to see what is happening.

1. As soon as routing rule matches, the message is destined to be dispatched through the legacy mail server.
2. Recipient address map matches, the original message is immediately dropped and a new one, with a new recipient, is dispatched (through the legacy route).

I have trashed the recipient address map idea and used Add another destination feature.