It's THAT EASY. IF you want to verify the hostname (att.net), you can have someone that has a "regular" camera phone, send you a photo, but send it as an email TO YOU. It will show you their return address in the format shown above.
It was the same way, back in the day, when you wanted to send an email to someone's phone as an SMS message, from an email client.
Come on, guys! Your lack of tech knowledge is lettin' me down!
btw, the phone also lets you save multiple email addresses per each contact you have in your list. So, I just save this address as one of their email addresses, and pick it from the list, when I wanna send them a photo.