help with my email account on my phone

I changed phones recently to the iphone e16 and having trouble with accessing my email; it allows me to send messages from my comcast email on my phone but it is not refreshing new messages to the phone.  I have gone to my cell phone provider T-Mobile but they said it is an issue with Comcast.  I am getting the error message :

Cannot Get Mail

The mail server

"imap.comcast.net" is not 

responding.  Verify that

you have entered the correct account info in

Mail settings.

Server code

AUTHENTICATIONFAILED; 

server messzge

"Authentication Failed."