Contact info showing in "To" of Mail messages

Hi all. I was just informed by a student today that anytime I respond to student emails from my phone, they are able to see my contact information (phone # and address) in the "To" part of the Mail message (they said they thought it was an iOS 8 thing). I double-checked that I was replying to emails from the correct account (I was) and I didn't see anything that seemed to link my contact info to that account in my search through my phone. Is there a way to block/stop my phone #, etc... from showing up on emails when I send them to others?

(If it helps: I have 2 email accounts on this phone - 1 which is personal, associated w/the iPhone + iCloud account, and 1 which is work).

Thanks for any suggestions.