Default SMTP route for each virtual domain

[Szymon K]

I have an idea to add default smtp route for each virtual domain.

Sometimes people use a few of smarthosts.

[Former user]

I need something like this in my poste.io since I have multiple virtual domains and the emails need to be sent via mailgun and each domain needs its own host+user+password.

[Jovan Jovanovic]

Can this be added? I also use mailgun and it requires a smart host per domain.