1771 Views 1 Reply Latest reply: Jan 27, 2010 7:15 AM by Tim Campbell1
That's the old name of the MobileMe service (it was previously called ".Mac" (pronounced "dot-Mac"). The mail domain still works and those with MobileMe accounts will receive mail regardless of whether the mail is addressed to email@example.com vs. firstname.lastname@example.org.
It's a subscription-based service which includes email as well as many other services.
Apple offers free trials of the service and part of the "out of the box experience" of buying a new Mac has an offer to try ".Mac" (now called "MobileMe") So if someone took advantage of this it would explain why you are seeing a .mac email address on your system. But if whoever opted to take advantage of the trial never purchased the annual subscription (or discontinued it) it would explain why you get an error message with the mail account when you try to use it.