yes. But that doesn't mean it's possible, or Gmail would be doing it too. they have PhD's and stuff. (or used to).

so for sure it isn't possible for some reason, even if someone else is doing it.

what other explanation can there be? why would they just have a glaring security hole like that, allowing anyone you try to give a trackable email to with + to just remove it with a regex? It doesn't make sense. there must be some reason it can't work.