If you are having problems logging into your email through Outlook, Thunderbird or other Mail Client, please check that the SSL/TLS is enabled.
Due to some recent changes with PCI Compliance Regulation we are being forced to disable the Plaintext Authentication on POP3 and IMAP. In your mail programs (Outlook, Thunderbird, Mail etc) you must change the settings for the Authentication Connection so that you're using SSL / TLS connection method. Upon doing this, you will also need to change the Server Connection so that it lists your domain name (if you have an SSL installed on your site) or set it to your current server's hostname.
Once this change is made, your POP3 or IMAP mail will work without any issue.
Reviewed : 11/13/2016