MailCow is similar except uses docker. I expect that will mean easier maintenance as it is less tightly bound to the underlying OS.

One time, in 2008. It was an envelope, tho.

Could be, although codeberg goes down more than anything else I use so this could be normal.

Like github, except open source.

A lot of fediverse-related projects use it.

During onboarding of a new account, https://piefed.social/ asks you this:

… and sets up an appropriate keyword filter based on your answer.