In the "compose an email" window, it would be helpful if there was a "schedule send email" or "send email in background" button. This can be used when sending big mails because it can take a while until the mail is send. In this time the "compose mail" screen remains open and the user needs to wait until the mail is send.

The button can send the mail/concept to the outbox and a job queue can then send the mail in the background. Automation of the "send mail" button on the "outbox" screen.

A button to call the enqueue mail functionality.