Testing credentials

Given DOMAIN/username/your.name is your username, and PASSWORD is your password, to test your login in plaintext mode (which is insecure), you can use:

$ telnet example.com imap

* OK Microsoft Exchange Server 2003 IMAP4rev1 server version 6.5.7638.1 (yourserver.com) ready.
a1 login DOMAIN/username/your.name PASSWORD
a1 OK LOGIN completed.

And for IMAP of SSL (IMAPS), you can test using:

$ openssl s_client example.com:imaps

* OK Microsoft Exchange Server 2003 IMAP4rev1 server version 6.5.7638.1 (yourserver.com) ready.
a1 login DOMAIN/username/your.name PASSWORD
a1 OK LOGIN completed.