Dear All,Sometime other need to read other mailbox email. I can grant full access in Active Directory User and Computer.Or user can set permission by using outlook.What is different between that?

The Full Mailbox Access works at Mailbox level. The Folder permission set works at Mailbox\Folder level. For your reference: http://msexchangeteam.com/archive/2006/05/01/426936.aspx Mike

Hello, To configure and leverage users mailbox permission in Outlook , please see KB291626: http://support.microsoft.com/kb/291626/en-us However, if you want to send email on behalf of others. E.g. If you are user A and want to use B as the sender to send emails ,i.e. use Bs name in the From field. If so, you have to add As permission in ADUC instead of in Outlook client. Hope this helps.