Hi,Environment:3 Windows Server 2008 DC1 DomainWindows Server 2008 with Exchange Server 2007!2 Hub/CAS and 2 mailboxservers within a CCR!Problem scenario:GlobalSecurityGroup01UniversalSecurityGroup01MailboxUser01MailboxUser02RoomA1. Adding MailboxUser01 to GlobalSecurityGroup012. Adding SecurityGroup01 to MailboxUser02 as Full Access Rights. (SecurityGroup01 icon is gray?)MailboxUser01 still can't see MailboxUser02's mailbox.When converting the GlobalSecurityGroup01 to UniversalSecurityGroup01 the icon is filled with color but still can't see the MailboxUser02's mailbox.When adding MailboxUser01 directly to the MailboxUser02 as Full Access Right, and removing the SecurityGroup we can open the MailboxUser02's mailbox.Questions:1. Is it possible to add Full Access Rights to groups?2. Shall the groups be Global or Universal?

Hi Ftornell, You can give the Universal Security Group full permission to access a user mailbox by using the following method: Add-mailboxpermission MailboxUser02 user UniversalSecurityGroup01 accessrights fullaccess If MailboxUser01 still cannot be access MailboxUser2 mailbox, please remove and recreate the UniversalSecurityGroup01 to troubleshoot the issue. Mike