I used to use + for that purpose and was always pretty annoyed when a website wouldn’t accept it. I’ve since dropped gmail for fastmail though so now I use [email protected] for all website registrations. No site ever rejects it and it works great for knowing where spam comes from, although I’ve had some funny phone calls where people were baffled that my email address starts with their website name.

> No site ever rejects it

Have you ever tried it on Yahoo? They wouldn't let me set my email address to yahoo@mydomain a few years ago, claiming that the "email owner" had blocked this: https://www.dropbox.com/s/t213wkajdz5753k/yahoolies.png?dl=0

Spammers already know the dot rules. Its fairly easy to identify a Domain Group (ymail/yahoo) or (google/gmail/somewhere.edu) and then strip and reapply certain rules based on what that Mail Provider allows.

That's true in theory. In practice however, I've had success with figuring out a service that leaked my dotted address (I used a dot because the service didn't validate email with plus). I think this is often the case too because, spammers don't really bother validating emails by postprocessing etc. and just sell the emails in bulk in shady markets

Thank you.. I use this feature in exactly the same way. As I read,I was sitting there thinking "I can't possibly be the only one who knows about,uses,and likes this feature". Disabling it at this point would seriously screw up my life. It also prevents people from registering all of those close variations of my gmail address, which I also like.