Brent, Here is more log information that occurs when using Avast Mail shield.

CERT: Pre-verification error: self signed certificate in certificate chain

Rejected by CERT at depth=1: OU=generated by Avast Antivirus for SSL/TLS scanning, O=Avast Web/Mail Shield, CN=Avast Web/Mail Shield Root

SSL_connect: 14090086: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed

This occurs in the POP3 connection.

Hope this helps.