[rootusrootus]

I'm not OP but I do something similar, which I can describe. I don't whitelist addresses, I have a domain with a catchall account. So I make up addresses as needed. When I want them to die, I add them to a ruleset on the server that punts them into the bit bucket.

So far it has been really great. Easy, effective.

Edit: Like the other reply you got, I use FastMail for this service.

[btmiller]

Here’s a good guide on how to go about this :)

https://btmiller.com/2019/12/12/regain-control-over-your-inb...

[theK]

Dito, have been doing the same with a selfhosted mailcow for years. Never had a problem :-) Lately I started switching over to [e-mail] style because of the automated organization so I don't need extra routing rules if I want to organize them.

[wombatpm]

Except for the sites that reject the + character in email. I curse those developers who do that and never go back to that site again.

[dkersten]

I do something similar and also use FastMail. I use <site-name>@sites.<my-domain> for all site signups, eg [e-mail]