Not sure about how to check what all Authentication Mechanism are available on IMAP running on Microsoft Exchange Server 2010 ?
Don’t worry here is a blog which explains this.
What Authentication Capabilities are available with IMAP depends upon what you have set in IMAP settings.
For this demo I have set EnableGSSAPIAndNTLMAuth to True using the below method:-
Open Exchange Management Shell on Microsoft Exchange Server 2010 that has the Client Access Server role.
Set-ImapSettings -Server FAB-DAL-E10A.Fabrikam.com -LoginType 2 -EnableGSSAPIAndNTLMAuth $True
Restart Microsoft Exchange IMAP4 service.
To know what Authentication Mechanisms are available on IMAP, we will have to follow the steps given below :
Open Command Prompt and telnet imap on port 143
Telnet FAB-DAL-E10A.Fabrikam.com 143
* OK The Microsoft Exchange IMAP4 service is ready.
* capability
* CAPABILITY IMAP4 IMAP4rev1 AUTH=NTLM AUTH=GSSAPI LOGINDISABLED STARTTLS CHILDREN IDLE NAMESPACE LITERAL+
* OK CAPABILITY completed.
For information about Managing IMAP4 please go through following article.