Does Exchange support plussed users (e.g. [email protected]) or a similar mechanism? [duplicate]

Since Exchange 2007 / 2010 doesn't support it, the only way would be to create your own MTA (Mail Transport Agent). Luckily there's (at least) one guy that already did the basics for you.

http://durdle.com/regexcatchall/

RegExCatchAll is a Transport Agent for Microsoft Exchange 2007 and 2010. It provides email suffix matching based on standard .NET regular expressions and can deliver email to Exchange Mailboxes or external SMTP addresses. It stores its configuration in an XML file which can be updated live without restarting any services. It also includes a “banned alias” list, so you can blacklist any of your previously used suffixes

HTH

No, Exchange doesn't support this. A similar feature (nicknamed "disposable e-mail addresses") was proposed for Exchange 2010, but it didn't make the cut.

I went into a bit of a wiki-hole on this one, based on an off-hand comment that Outlook.com supports this from a source article for a linked question (it doesn't, really). Outlook.com obviously runs on Exchange at some level, so I simply had to satisfy my curiosity.

If you're an Exchange admin, you can create a mail contact for whatever you want at your domain, and have it deliver to the destination of your choosing. This of course does not equate to the ad-hoc usage of user+subject@domain.com.

If you're an Outlook.com user, you can apparently create an alias at http://mail.live.com/?rru=createalias, at a rate of up to 5 per year. This also does not equate to the ad-hoc usage of user+subject@domain.com.

I'm not saying definitively, but sending to my username "+test@" work (E2k3) email did not come through. I'm not willing yet to say that it doesn't work at all, but it doesn't work in my environment.

Also a cursory search of the web does not come up with any references. It may be possible to enable this behavior, but I don't know how.