Person not receiving my mail

This problem was solved and then not.

I have tried to get mail to a friend that has a ntelos.net address and someone, carrierzone.com, connected with COMCAST keeps sending it back with a lumos.net address that does not exist.  They have the correct address but, for some reason, they reject the mail with another address.  Does that make any sense to you?  Me neither.   There was a lot code included with the returned mail and I would love to get that to COMCAST but trying to get anything to those people is whole different story.

Maynard