Recently, while working on integrating an email notification tool with a client’s Exchange 2007 IMAP services we encountered several errors. The errors included:
- “Connection is closed. 14 “ when attempting to telnet to the secure IMAP port.
After walking through the Exchange configuration with our client it became apparent that the issue was likely related to an expired Exchange SSL certificate. I proceeded to reissue a new certificate and found this article helpful:
Creating a Certificate or Certificate Request for TLS
http://technet.microsoft.com/en-us/library/aa998840.aspx
Especially helpful was the section on “Cloning an Existing Certificate”. According to this article, Exchange 2007 self-signed certificates are only valid for 12 months.
After I cloned/reissued the old certificate the errors in all our different IMAP test clients went away.