missing emails

I have been a Comcast mail user for many years. Up to and including January 2025 I was receiving at least six new emails into my Comcast mail in-box every month. Since the end of January there have been no new entries in that mailbox except for one that claimed to be from Comcast but looked like a scam.
 I tried to send a test email from my Yahoo email to my Comcast email but that mail did not show up in any of my Comcast mail folders. On 7/7/2025 I did successfully send a test email from my Comcast account to my Yahoo account, but I did not hear back from an email I sent from my Comcast account to support@xfinitymobile.com so I presume that email did not get through. My Comcast sent folder is missing all my sent emails from 4/2018 to 7/2025. I have received five emails in my Comcast junk folder in the past week.
I am seeing the same problems if I open Comcast email through the xFinity web page or through Outlook, and the same on PC, Laptop, iPad or iPhone.
I’d appreciate any help or advice on how to get my Comcast email in-box to start accepting incoming mail again.
Thanks