Exchange 2010 I am having issues with Calendar ACLs working properly with MailUniversalSecurityGroups I am able to add permissions using the add-mailboxfolderpermission cmdlet for both user objects and MailUniversalSecurityGroups My problem is if I add new members to MailUniversalSecurityGroups the permissions do not take effect for those newly added users however the list of users that are already members have the correct permissions to the said resource calendar also If I create a new MailUniversalSecurityGroup and assign permissions to the new group these permissions don't work either; but the group does show in the ACL for the calendar with the correct permissions Also I can add permissions to MailUniversalSecurityGroups that were created in the past and these permissions take affect for group members Replication appears to be working fine between AD servers and If I add users to the resource calendar ACLs the changes take affect nearly instantly Any help on this would be greatly appreciated... is there some kind of weird replicachiness that im not aware of...that would last for over 5 hours?

Hello, For the mailbox permission, you have to set them one after one by the Set-MailboxPermission CMD. Thanks, Simon