I will soon be enabling the ability for users to have a custom email@example.com email address along with the ability to check it via a webmail interface.
What the requirements for obtaining this function hasn't been decided yet. I doubt it will be a paid option - most likely based upon the amount of participation you do on the site.
It's not going to be a Google size setup (because I don't have the deep pockets that Google has) but you will have 20MB of storage. This should be enough for most usage of common email patterns (not heavy on photos but primarily text). The email accounts will also have spam filtering and virus checking on them.