The Administrator and Domain Admin accounts are explicitly denied access to all mailboxes by default, although they have full administrative rights over the Exchange system. All Exchange Server 2003 administrative tasks can be performed without having to grant an administrator additional rights to access everyone's emails.
The VSA requires "send as" and "receive as" rights for it to fully function as it will need to be able to access all mailboxes on the Exchange server it is processing.
1. Open the Exchange System Manager (ESM), expand Administrative Groups, then First Administrative Group, then Servers. Select the Exchange server from the list, right click your Exchange server object and select Properties. (Figure 1)
2. Select the Security tab, from the list of users under the name box find and select the VSA. (Figure 2)
3. Click Advanced to open the Advanced Security Settings for Exchange Server window and click the Permissions tab. (Figure 3)
4. Click Add and select the VSA from the domain user list. Click OK to add the account. (Figure 4)
5. The permission entry for the Exchange Server window will open. In the allow column, select Receive As and Send As shown in Figure 5.
6.Click OK to return back to Advanced Security Settings for the Exchange Server window.
7. Click Apply and then OK to update these permissions for the VSA and return to the Exchange Properties window.
8. Click OK to close properties window.
9. Close the ESM.