After almost 2 hours we found the problem.
Comcast has marked our
[email protected] address as SPAM. Default settings on the Xfinity email account are to enable spam filtering and NOT save a copy. This can be found in the Settings / Advanced Settings near the bottom for each Xfinity email account. Enabling both Spam Filtering choices will put all spam into the spam folder on the server. At least you can see what is being filtered.
This has been escalated by Comcast tech support to remove this address from their spam list which is administered by a third party. may take 72 hours.

... if you are missing incoming emails go on-line to your Xifinity Connect and make sure the settings are correct. If emails are being sent to spam you can see them then you need to call Comcast to get help 888-565-4329 (8am-8pm)
I hope this helps others.....
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