[Feature Request] Add e-mail domain blocklist

[MightyPork]

Feature Description

I would like to ban registration from gmail.com, due to the amount of activated (!) spam accounts from there.
I get over 20 every week, with hCaptcha enabled. They are usually ads that exploit the URL field in profile bio.

Blacklisting gmail is not the best solution, but I believe hCaptcha is not working because these are not bots, it's Indians doing it manually. (Guessing by the kind of ads I get there). Most real users who come to my gitea to file a MR or an issue have their own blog/domain and use that for the e-mail.

This is essentially #4305, but implemented as a blacklist, not whitelist.

Screenshots

No response

[MightyPork]

I just had an idea how this proposal could be improved - a kind of "graylist" where - if the e-mail domain matches - the account would be queued for manual confirmation.

That way, people who legitimately use the banned domains can still get in, but spammers are, hopefully, blocked.

[lunny]

But that will make more maintain things.

[theAkito]

Really good proposal. This is a very common issue. A queue for manual confirmation would be great. Even, as a global flag for every single account.

[wxiaoguang]

Already done by Allow blocking some email domains from registering an account #14667 ?