When you attempt to add a user to the Mailbox Manager, the user isn't added but not error message is displayed. Looking at the AOnePolSnap.log, you see the following error:
13 09:32:54 474790 *** INFO:Starting:Start of add item to mailbox manager
13 09:32:54 480737 PermManager::IsValidLicence
13 09:32:54 483682 PermManager::IsValidLicence returning cached validity
13 09:32:54 489652 PermManager::GetServiceInterface() pinged service 0x0
13 09:32:54 492596 InfoNode::EnsureLoggedIn call to GetServiceInterface returned 0x0
13 09:32:54 495903 SetAppNameOnDialog called for dialog ''
13 09:32:54 513180 StoreWrapper::GetAddressBook OpenAddressBook failed 0x40380 MSG1268: Failed to connect to Exchange
13 09:33:02 064231 *** INFO:CompletedSucessfully:End of add item to mailbox manager
The ArchiveOne service account is unable to access the Global Address List (GAL). This issue has only be observed on Exchange 2007 SP3 environments.
As a workaround, you can configure a static MAPI profile for use with the ArchiveOne Service as per: How to Configure ArchiveOne to Use a Static MAPI Profile