Email address plussing no longer supported?

[jayr]

With the old mail server, address plussing used to work. What's plussing you ask? Its a commonly supported feature of most Unix mail servers, where a + can be used after the username to add extra info to the email address. So when you register with some website that you think might sell your address to spammers, or if you just want to easily filter mail from them without knowing what email addresses they might use to send from, you could register your address as username+website@f2s.com, and mail would get through to username@f2s.com.

I'd registered with amazon like this, and two days ago bought something from them, but haven't received the normal mails. Mail seems to be generally delayed at the moment, so I don't know whether its held up in a queue somewhere, or the new servers don't support plussing anymore. Can someone from f2s confirm if support for plussing has been dropped?