Sendmail supports a feature called 'plussed users'. Once enabled, emails sent to
are automatically delivered just like mails to [email protected]
. There is no need to register or set up these 'plus suffixes'. The user can just use them and set up client-side filtering rules on his own.
Does Exchange support a similar mechanism? If so, how to enable it?
Note that I don't want answers about other means of filtering, e.g. spam/junk filtering, server-side or client-side rules, email aliases/addresses that are configured explicitly and so on.
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/
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.