IMAP server

I have a bizzare situation. I have two IMAP comcast accounts. This AM, one of them stopped working, saying the IMAP server rejected the connection.

This happened on both my PC Outlook app, and my iPhone mail app.

I can access the account on xfinity.com, and all seems good.

The other account has no problem accessing from the PC (I don't have it on my phone).

Tried all the tricks, deleting account on PC and phone, reinstalling MS Office, changed passwords, etc.  Still no luck.

Comcast technical support was no help (they just suggested all the things I tried), and they wouldn't elevate it up to a more technical level --- and tried to blame Outlook. 

I am at a loss.

Anyone ??

thanks

Kevin