Earlier quoted context omitted.
You can use the + trick and . trick with Gmail addresses too. I think Outlook as well supports the + trick. The only downside to this is that there are plenty of sites that don't accept a + either knowingly or unknowingly.
I think most MTAs support +. Isn't that part of the e-mail standard?
So the fact that the MTA will route it is irrelevant if it never makes it to the MTA in the first place.