Block full email addresses similar to IP Blocks

[shleeable]

Pitch

I only recently noticed that email blocks are whole domain blocks, and not single email addresses.

Please copy the IP Block UX with the same format for emails.

Due to "PII", please support email address in full or a SHA hash of the email address.

8387bcf5d48817b33843692dc9034827627352d37b55b1408ca96de9cfe2e774 is bob@bob.com in sha256 (allowing "safer" block lists to be created)

Motivation

I want to start sharing a blocklist of spam emails with other instance administrators.

If this is accepted, please consider supporting the suggestion I've made in #19038 (comment)_ to allow people to maintain blocklists.

[ThisIsMissEm]

How would you know if a rule here is a domain filter or a address filter?