While trying to set up an email queue in the email parser on Kayako Classic, you may encounter the error "IMAP connection broken (server response)." This article provides information about this problem.
The error message tells us that Kayako Classic is unable to connect to your mail server to be able to parse emails. The mail server either refuses the connection from Kayako or getting timed out.
The problem needs to be diagnosed and fixed from the mail server end. We recommend that you get in touch with your mail server admin to check the logs on the server and fix it accordingly.