[thmzlt]

You can do that in FastMail (web UI or mobile app). It supports multiple domains too.

The compose view looks like this: https://imgur.com/a/qULeL5a

[crossroadsguy]

Oh. Undo tuna I’m on mailbox.org and I was looking for a mobile and desktop client rather than a provider. But yeah I’ll definitely consider them the next time I’m looking to move mail provider.