Members of group ldap attributes are not getting updated

==== Required information ====
- iRedMail version: Pro version 2.0
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  LDAP
- Linux/BSD distribution name and version: centos
- Related log if you're reporting an issue:
====

Hi zhang,

I have deleted a mailing list, But users are able to send mail to that mailing list and mails are getting delivered. When  i search for the mailing list in the iredadmin its not there.

My Findings,

I just analysed the ldif file of a user in the memberofGroup attribute the deleted mailing list is shown. I think whenever i delete a mailing list its not updating  the membersofgroup attribute of users ldap.

Note: I have more that 1500 users in a the system.

Thanks