Migadu supports custom domains and is one of the few email providers that does not limit the number of domains, aliases or mailboxes. Instead their pricing is based on storage and the number of emails received and sent.

It really is too bad we dont have a federated github alternative. I know theres some projects in development, but I can see the emulator scene getting harder and harder to get into if popular repos go down. Decades of work, gone.

There is Radicle which is a peer-to-peer forge.

Edit: Don’t expect all the features of GitHub or Forgejo though.