Zimbra IMAP (Outlook, Thunderbird) vs WebUI passwords

[sanjeewa]

Hi,
I am planning to deploy Zimbra Network Edition in a production environment and as a pilot project I have Zimbra Open-Source edition (Release 7.1.0_GA_3140.DEBIAN5_64 DEBIAN5_64 FOSS edition.)

set up to authenticate against External Active Directory. (AD only)

Issue is, When i change the password in the Active Directory user account, and try to log in to zimbra using webUI it picks up the changed password immediately and rejects the old password. This is exactly the expected behavior!

However, if I try any IMAP Client (TB/ OUTLOOK) they dont pick up the changed password. They still authenticate with the old password, and rejects the new password.

Is there any logical explanation for this scenario ?