Send from different email address (email aliases)

I use Fastmail, so my login credentials involve an email address. However I don’t give this email address to people. Instead I have an email alias using my own custom domain, and this is the address I want to share with other people.

Is there a way to set up Delta Chat so it sends email from a different address than the one I provided for my login credentials?

I’m currently a little bit in hurry.

But I think it should work similar to this:

It would be great if you could feedback if it’s work.

Aha! Ok it took a couple tries, but it worked.

  1. Change your email address to the one you want to use with your custom domain.
  2. Under advanced settings, specify your login email address in both IMAP and SMTP settings.
  3. Also set your IMAP and SMTP servers! Otherwise it’ll try to use servers at your custom domain. For Fastmail, that’s and

Not very straightforward, but if you’re using a custom domain, you’re probably technical enough to figure it out.


as a user of fastmail you might want to add your findings to our (work in progress)provider overview