Apple’s iCloud service (formerly Mobile Me, formerly .Mac) offers email aliases for every account. Aliases are a feature common to many email services. iCloud allows each account to enable up to three additional email addresses without having to pay for or manage three additional accounts. They are useful as temporary addresses for online purchases to avoid spam or as long-term addresses that are more memorable than the account name.
For example, if my iCloud account . . .
Continue Reading: Configure Outlook for Mac to use iCloud email aliases