This is a short tutorial on how to add full access to all mailboxes in Exchange 2007 and 2010 for a an additional user. This can come in handy when say migrating to Office 365 in which you need your migration account to have full access. We were surprised by how many variations we found, so we decided to post one.
Exchange 2007/2010 Full Access Instructions
Launch the Exchange Management Shell.
Type the following and press enter; replacing “name_of_database” with the name of your Mailbox Storage Database and “name_of_user_account” with the name of the user you are wanting to have full access rights:
Get-Mailbox -ResultSize Unlimited -Database "name_of_database" | Add-mailboxpermission –user "name_of_user_account" –AccessRights FullAccess
The names of your databases can be found under “mailbox” under the Server Configuration in the Exchange Management Console. Click into the database management tab.
You can also grant full access permission manually one at a time by right clicking on a mailbox in the Exchange Management Console and selecting “Manage Full Access Permissions.”
You can read more about this here: http://technet.microsoft.com/en-us/library/bb676551%28v=exchg.141%29.aspx