Mailboxes switch with data missing in target - resynchronizing brings over all data (4271617)

Mailboxes are switching even though mail data is missing in the target mailbox.

No PRV files are queued up in the target for these users.

A resynchronization of mail data brings all the data over successfully.

Why is this happening?

This may occur if the source mailboxes once participated in another migration in the past.

If the source mailboxes already participated in a migration and a Quest product (QMM or EMW) was used, then the mailbox will contain hidden replication stream messages.  These messages will be read by the Mail Source Agent (MSA) and cause it to only synchronize data since the last MSA session in the previous migration.

Because of this, the MSA will switch these mailboxes, believing it has synchronized all of the data.

There are two methods to resolve this issue:

1. Configure mail collections to perform a full resynchronization when you first create them.  This will force the agents to delete the replication stream from the source and synchronize all data.

2. Use a script to clean all source mailboxes that participated in the previous migration.  This will delete the replication stream messages and prevent the issue from occuring.

This script can be found here:

https://support.quest.com/Search/SolutionDetail.aspx?id=SOL15731&category=Solutions&SKB=1