Apple MOBILEME services : ADDRESS
If you have a Macintosh, and you have subscribed to a "MobileMe", you can have a personalized email address "me.com" (example: amy.lol @ me.com). This address email offers many advantages. I propose you to discover how to set up "Mail" and what are the advantages of such an address.
If (and only if) you already have an account with "Mac," your address "mac.com" is of course valid. You have the option to use either indiscriminately email@example.com, the firstname.lastname@example.org for your email address (amy.lol @ me.com or amy.lol @ mac.com).
This is exactly the same mailbox. That you write email@example.com firstname.lastname@example.org, your emails will go to the same mailbox. No need to create two separate accounts in your e-mail.