Avast preventing Windows Live Mail from functioning

[REDACTED]

We were using Windows Live Mail as an interface for IMAP accounts with Gmail.  Everything was fine for months.  This weekend, we kept getting error messages when trying to send and receive or trying to update our IMAP folders.  Errors such as 800ccc0e or 0x800CCC0E, with different descriptions such as "Your server has unexpectedly terminated the connection. Possible causes for this include server problems or long period of inactivity."  We have other computers on our internet and they are having no trouble accessing the same Gmail accounts using IMAP.  They do not use Avast. They use another solution. The one computer with Avast is having all the problems.  IF we turn off Avast for 10 minutes, we can send, receive and function normally.  Please help.

[Eddy]

Disable the avast signature in the emails and check if that is solving the issue.

[REDACTED]

Thanks for the answer.  I removed the signature and it didn't make any difference.    The latest error message is:

Unable to send or receive messages for the xxxxx account. Header download for the 'Inbox' folder did not complete. Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity.

Server Response: Your IMAP command could not be sent to the server, due to non-network errors. This could, for example, indicate a lack of memory on your system.
Server: 'imap.gmail.com'
Windows Live Mail Error ID: 0x800CCC0E
Protocol: IMAP
Port: 993
Secure(SSL): Yes

AFTER receiving this error when trying to send, I once again turned off Avast and it sent email just fine. 

[Eddy]

Does it work if you disable TLS/SSL scanning in avast ?