It only works if you set up an "identity" for every possible e-mail address that you use.
If you use e-mail the way that phildawes and I do - that is, using a catch-all for your domain and giving a different e-mail address to each organization - then you would have to set up an "identity" for every e-mail address you've ever used in your life. For me, that number is in the hundreds and I don't have a list of all the ones I've used.
If I'm wrong, however, then please give more details on where to find this feature!
If you use e-mail the way that phildawes and I do - that is, using a catch-all for your domain and giving a different e-mail address to each organization - then you would have to set up an "identity" for every e-mail address you've ever used in your life. For me, that number is in the hundreds and I don't have a list of all the ones I've used.
If I'm wrong, however, then please give more details on where to find this feature!