[lgl]

You could have also used "plus sign" addressing if your e-mail provider supports it.

For example, gmail supports it so if your email is [e-mail] you can register for services using [e-mail] and it will end up on bob's mailbox.

While this is useful, please note that this is not as private as a catch-all alternative as one can always infer the actual e-mail address by just removing the plus sign and everything after it while using a catch-all you can completely obfuscate the actual username.