Blocked Xfinity Comcast IMAP email connections from outside the US

@jsifantu

This link Xfinity ⋅ Service Policy Assurance where you can report your issue

I've tried to the Servicce Policy Assurance site you mentioned. However, the form requires providing the domain and IP address from which I'm experiencing the problem as if its specific IP address would be blocked. First, I'm not sure what the domain is in this case since I'm using an internet connection provider modem from my home in France. Second, the problem is with the authentication while trying to connect some of the email clients to the Xfinity Comcast IPMAP/SMTP servers, mostly the clients on my mobile devices, such as Outlook or Apple Mail on iPhone and iPad M1 or Outlook on Android on a Samsung phone. Access via the Comcast Web email application works fine. So, I'm wondering why the authentication fail on some clients but not on others. And why did this start happening all of the sudden while it has been working for months. 

Thank you for you answer, but I have tried this before by switching back and forth multiple times, but to no avail. Still the same problem. This additional security option was already on when the problem started to happen. And, for and additional puzzling aspect, the Outlook application configured on the Mac can connect successfully from the same location without problem. So it seems this problems with authentication only happens from email clients on devices running either iOS or Android. Very frustrating.

@jsifantu Can you please uninstall and reinstall Outlook? We have come across other threads with a similar issue to this and customers have reported that has been a successful step in resolving the issue.