[dimitar]

They look great! However I don't seem to find an option to use a custom domain.

[nachtigall]

+1 for Posteo, but they do not offer custom domains. See 3rd question at https://posteo.de/en/site/faq

If you want this, then I'd check out https://mailbox.org

See https://mailbox.org/en/how-to-use-mailbox-org-with-individua...