I am migrating my emails from current iPlanet to new Zimbra server. I keep getting this error when using imapsync. I can transfer mail using fetchmail but i intended to use the imapsync --syncinternaldates feature which is good.

Banner : * OK relay1.kukum.edu.my IMAP4 service (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004))
Banner : * OK email.kukum.edu.my Zimbra IMAP4rev1 service ready
Error login : [] with user [aizudin@email.kukum.edu.my] : 3 NO cleartext logins disabled

the error is from the Zimbra IMAPrev1.

Any ideas? Thanx..