The easiest I found was to use gmail. Gmail allows you to tag usernames, so if you're email is my.email@gmail then you can use:

my.email+1@gmail
my.email+2@gmail
my.email+3@gmail

etc.

It will all go to your same gmail account and dmm recognizes them all as different usernames. Once you're have a roll that you want, change your email at dmm to whatever you want.