We're currently researching what is causing the email address to be added on the contacts. I would suggest you to delete/edit the contact in the mean time and, if there's a message thread to that email address, delete it as well.
Shouldn't my name be listed as a participant in the text? It's not but firstname.lastname@example.org is listed.
When I click the 'i' it's listed but doesn't show a location. When I click on the name from the location or 'i' screen and then click on the name again a message pops up that says:
You followed a link that requires the app "Mail", which is no longer on your iPhone. You can restore it from the App Store.
Show in App Store