Email should work after we disconnect from Xfinity, but...

I moved to a location where Xfinity is unavailable, but up until today I've been able to use my Xfinity email address without any issues as promised. But suddenly, very late last night, I couldn't access my email on my cell phone, though I was able to access it on my PC.

An error message kept saying that my login credentials for imap were incorrect, but I was still able to receive and send messages on my PC despite that. Not so lucky on my cell.

What's happening? I haven't changed anything since I moved and I have used that same email address continuously since that move as well--there's been no time lapse. I tried chatting with someone, but after taking my phone number so that someone could call me back, I've heard nothing.

I was a very loyal customer for many years and I don't want to lose all the email info I've had throughout those years. What can we do about this?