Shared hosting plan with email and a catch-all address (the latter being key to the whole thing).

Everyone I give an email address out to gets a unique one in the form: theirname.myname@host.tld.

As an added bonus, I have a place for blog, website, and reliable long term picture/file hosting.

Well worth the $20-30 per year it costs me (per domain), IMO. I have one domain for my IRL identity (my family surname), and others for pseudonyms.

iOS does it automagically if you didn’t know. Fastmail gives you 600 but with your comment now I want a plugin to do it from the browser.

https://simplelogin.io and https://anonnaddy.com Do exactly that, both open source and self host able, and support replying from the alias(paid)

SL has been acquired by Proton, and is now included in Proton Unlimited for free.

httpa://simplelogin.io exists.

Gives you unique alias for every service, owned by Proton.