On gmail when I have to give my email to a company, I give it out as myemail+theircompanyname@gmail.com, which is an alias for myemail@gmail.com. In theory I c

On gmail when I have to give my email to a company, I give it out as myemail+theircompanyname@gmail.com, which is an alias for myemail@gmail.com. In theory I could later use it to know which company gave out my email, but I also realize how easy it would be for the spammers to just remove the "+theircompanyname" part. Sometimes sites must be using a crappy regex that won't allow the + though, even though it should be a valid character in email addresses.