I do that in a fine-grained way with my personal domain: I receive mail addressed to any user at the domain. I never give out the same address twice. I can filter mail based on the "To" field, and always know how senders ultimately got my address. It works out because spammers never send mail to random other users at the same domain; I think trying unconfirmed users would be a quick way to get themselves blocked by common spam filters.

A fun thing I found this way: Samsung won't let you sign up for an account if the string "samsung" appears in your email address. Must be annoying for [email protected]!

I have a dedicated, very generic sounding domain name just for signups.

I use a custom email for each service. Like [email protected] for Amazon, xyz.ycombinator@... and so on.

All email is forwarded to a single catch-all account from a good provider, so it is just as convenient to use.

But it is trivial to isolate what emails came from which service, who has leaked my email to spammers, to just block a individual recipient, ... . It also makes it easy to have multiple accounts without the annoyance of a fallback email.

I wish I had switched to this method much earlier.

Ideally that domain would be used by at least a few hundred people to prevent associating via domain name though, with different prefixes (see xyz above) for each user.

For over a decade I've used hushmail's aliasing feature which allows you to create such custom emails (e.g. [email protected]) on the fly almost instantaneously. I use one per service that requires an email to sign up. Works great.

You can do it with the free account, too.

Just delete one if you are obviously getting spam because of a service selling their email lists. Which is a reality for "free" services. Bonus points because you can identify exactly who it is that is doing this and have the option of publicly shaming them.

I do this too and it’s great except for services that use the reply-to/from as a requirement for service emails.