[Crosseye_Jack]

I used to do this on gmail too before swapping to my own domain. On gmail you can use + to create aliases on demands. If you username is Foo.Bar and you are signing up to example.com you can use the email address “[e-mail]” and it will land in your inbox.

If a company leaks your email or stops respecting your choice about how they email you, you can just blackhole that [e-mail] straight to trash.

If a service refuses to allow you to use + in your email address you can use the period “hack” (I call it a hack, cause iirc it was meant as impersonation protectionand not meant to be used this way). On gmail your username can basically have as many or as few periods in it as you like. So using the Foo.Bar@gmail example foobar@ f.oobar@ fo.obar@ Fooba.r@ etc etc etc all work. You will just have to keep track on which username&period combo you used on X service yourself.

[jrootabega]

This will work if the sender is just incompetent or uncoordinated. If they want to keep sending you spam against your wishes, they will just normalize back to your base address. you could keep a dotted form that you only share with entities that you trust absolutely, but that seems fragile