On Apple's end, iMessage also supports email addresses as a user identifier (and it's the only one you get if you don't have an iPhone with an assigned phone nu

On Apple's end, iMessage also supports email addresses as a user identifier (and it's the only one you get if you don't have an iPhone with an assigned phone number). It's still not sending emails, though. The iPhone Messages app sends SMS, MMS, and iMessage; email is the responsibility of the Mail app.