[Samba] Outlook prompting for password after domain(samba 4.1.9) login password change

[Yan Jen Chen]

We have a samba 4.1.9 as a active directory domain controller and a police
to
change the password every 42 days.

When our users change their domain login password , their Outlook will
prompt for their
email password.

Our  active directory domain is @abc.com and our email is @xyz.com.

Our email system is Qmail , so the email password and domain login password
are stored on different system.

I am looking for a reason that Outlook thinks their email password has
changed when they have changed their domain password.
If users put in their same old email password again to Outlook, it works
and stops prompting.

Any suggestions?

Thanks,

Frank