I went to Google with 0x800CCC0F.  I saw many replies from Community that apparently worked, but all involved SMTP or POP3 protocols.  I have IMAP, so I hesitated to try any of those fixes.

I am using Windows 7 and Windows Live Mail.  (I fixed this once before with a Community expert's instructions when Microsoft stopped supporting Windows Live Mail  on Windows 7.)

The problems started suddenly, and include getting headers downloaded without the message itself (half white envelope icon).  The messages eventually do come down without any knowable effort on my part.  Slow in moving messages from one folder to another.  Here are some error messages:

--- I pasted prints of 4 error messages here, but they did not go with the text.  Here are some excerpts:

Your server has unexpectedly terminated the connection.

Unable to send or receive messages due to non-network errors.  IMAP command could not be sent to the server.  The server refused to accept it.  Server: imap-mail.outlook.com. ---

Any way I can send you these non-transmitted images?

I also tried the "Repair" feature for Windows Essentials 2012.  It said the repair was successful, but nothing actually changed.

Can you help?  I am not knowledgeable in computers, so please reply with all steps, even the minor ones that you might assume I would do automatically.  Thank you.

***Post moved by the moderator to the appropriate forum category.***