[janalsncm]

I see this recommendation everywhere and I am genuinely surprised that it works. Any spammer can find out your real address since there is an obvious mapping from + addresses to your real address. An actual solution would hide this mapping.

[bachmeier]

Yeah. Fastmail masked addresses are random. The best you can do is guess that an address might be masked, due to it not being [e-mail], but it provides no information about your real email address.