@Again​ ,    I am currently running Windows 11 and have been for almost a year without issues until the Nov. 2022 time frame, up to that point everything worked without issue.

I will try to provide in the order of "fixes" that I have tried:

Thru Microsoft Outlook, the "repair" function under the file system for Outlook

Manually determining correct email setup from Comcast, to include port addresses, and ensuring that "allow 3rd party access was checked"

Deleting and account and reinstalling ( this was problematic in that when trying to complete the setup of the "new" account it would fail with the "connection to server was interrupted" error message,  that is when, like others, I found that after a certain time in the evening it would allow me to complete the process.  ( I believe it was around 7pm-8pm Eastern)

Called both Comcast support and Microsoft support and spent several days back and forth with each providing information, and even allowing the Microsoft tech access to my laptop in an attempt to resolve the issue, only to be told that everything looked good in Microsoft, but because he was unable to resolve the issue he escalated the case to a higher tier support.  At this point when the higher tier support tech called is when he advised that he has been working with a number of Microsoft customers with the same issue.  He also advised that Microsoft was working with Comcast to resolve the issues.  This was in the late November early December time frame.  He stated that there would be an "update" at some point when they had identified the cause and a fix for it.

Since then I have read through the forums on the subject on the Xfinity forum pages  and have tried all of them.  Changing from a DNS to Dynamic DNS through my Netgear router with no success.  Current DNS is Google Chrome, IP: 152.86.65.5,  Primary 8.8.8.8  Secondary  8.8.4.4

I have also contacted my ISP (BrightRidge, with a 1GB fiber connection) and they have checked and tested my hardware upto the router and all is working properly according to them. 

As a note:  Outlook is my primary email program and has been for a couple of decades,  with no issues until recently,  I also have a secondar gmail account for streaming purposes and my gmail account has continued to work throughout the time frame.

I will try the provided link/fixes and see if any of them will help.

Thank you for your assistance, I will let you know

Steve

@user_164a07​ 

You mention your ISP is BrightRidge.  Does this mean you're no longer a Comcast customer and still use your @comcast.net email?

@Again​ Yes, have been that way for about 2 years. When we moved to a new home, did not have "Comcast in the neighborhood",  Comcast told use that we could continue to use our emails without any issues.  All worked fine until Oct/Nov of 2022 when this issue started

 "Cannot send email... (0x800CCC0F) Connection to server interrupted"

 if you search the heading above you will see a number of users who have had the same issues starting back in 2021.  Most of those folks have been Comcast customers and are no longer have an account but still use their Comcast emails.  

@user_164a07​ Again,  I have looked over the links you provided and they do not seem to address the issue that I am having.  

Thanks for your input

Steve