SMTP Proxy

My Firewalla Gold arrived yesterday, loving it so far. :)

My network scanner can send documents via email, but it can only authenticate to an SMTP server with username and password, and my SMTP provider only supports apikey authentication, so I need a proxy between them.

Previously I was using an ASUS router, with AsusWRT-Merlin, where I used E-MailRelay, which worked fine.

Before I adapt the same solution to FWG, I would like to know if there is a more "Firewalla-native" solution for this problem.