 Cleartext logins?
If Thunderbird is trying to log in without using TLS, the default configuration won't allow it for security reasons. Try configuring Thunderbird to either:
(a) send a STARTTLS command [not sure how to do this], or
(b) use sIMAP on port 993 [Account Settings > Server Settings > Use Secure Connection].
Or you can even (c) use the admin console to enable cleartext IMAP logins. |