Officials told MacNN on Friday that it recently became aware of an "internal error during routine testing that resulted in customers using .Mac domains being asked to change their e-mail address in order to access to their Windows Live IDs." "A Windows Live ID is the sign-in and password that customers use to access Windows Live Messenger, Hotmail and other Microsoft online services," the company said in a statement. "Access to Live IDs has been restored to our customers who use .Mac domains. We regret any inconvenience this caused for our customers." The service blockage appeared to be directly linked to Mac owners, as users with accounts from the likes of Gmail indicated no disruptions.