FWIW, within the last few days we are still getting e-mails from people using @comcast.net addresses. If that's the issue, perhaps the change is being staggered or phased in at different times in different areas. Cory, if you are still receiving and sending other mail successfully using that address, I'd suggest writing to email@example.com to ask for some help. It sounds as if WikiTree isn't recognizing your address. Since it's now weekend, you might not get an immediate response, but in the meantime try looking through the 'Related Questions' below these posts and see if you can find anything that might help.