Hi, I've setup secure IMAP on Exchange 2007. All works fine. What I would like to do is setup plain IMAP (Port 143) to work as well. What would be really great is to be able to provide normal imap to a few mailboxes and secure imap to everyone else. Any hints? Regards, iss

I don't want to setup two CAS servers. Iss

Hi, I have answered the similar question about POP3, you can view it for your reference. http://forums.microsoft.com/TechNet/showpost.aspx?postid=3790532&siteid=17 The mechanism of the IMAP is the same as POP3. Thanks Allen

Hi Allen, Your post very helpful. I just wondering if you were to publish an IMAP service externally through ISA Server, what would you use IMAPS (993)or IMAP (143)? According to your post I would use IMAP (143). Regards, Iss

Hi, For secure communication, please use 993 port, for normal communication, 143 port is used. The prerequisite of keeping two ports available is you should set the authentication of IMAP4 as Plain text logon (Basic authentication). No TLS connection is required for the client to authenticate to the server. Thanks Allen