[BeetleB]

Years ago, I considered your approach. Programmatically create a custom email address for each person I wanted to talk to.

Then I hit upon a simpler solution. Have one email address. Happily share publicly. And whitelist the sender's email addresses. Emails not in the whitelist go into a quarantine folder that I glance at once in a while.

It's almost equivalent in efficacy, but much simpler to implement.

[ProllyInfamous]

I don't have a phone ringer anymore, but when I did whitelist-only is how I screened incoming calls. Your method for email sorting has the advantage of being reviewable (verse entirely blocking specific handles@) — and much easier to implement/maintain.