Too much or unwanted data is migrated to the target Exchange from a deleted message store known as the Exchange 2010 dumpster.
The dumpster is a location that deleted email go after a user has removed them from their mailbox completely. These deleted emails hang around for a retention period of x amount of days which is configured by the exchange administrator. This is not the deleted items container in outlook or OWA, it is a special place for emails removed entirely from the outlook interface.
Migration Manager will copy the dumpster emails from Exchange to the target enviroment unless configured not to.
The SkipDumpster configuration parameter has been added for the Mail Source Agent. When this parameter is set to 1 in the Mail Source Agent configuration file, the Exchange 2010 dumpster will not be migrated. Use this if you are sure there will be no need to restore deleted items in the target Exchange organization after the migration. By default, the value of SkipDumpster is 0.
Note: This does not work for Remote User Collections (RUC) collections. Nor will this setting work with Exchange 2007 / 2003.
1. Goto QMM console | Tools Menu | Options.. | Additional Parameters for Agents configuration Files
2. Select the "Add..." button.
3. Enter "SkipDumpster" as the Name for the parameter.
4. Set the value field to "1".
5. Apply to "Mail Source Agent" from the dropdown pickbox.
6. Select Ok and the Ok again.
7. Reapply the agent configuration for the Mail synchronization to ensure the agent is updated.
To see the Additional parameters for agents configuration files you need to enable it via the registry on the console. Open Regedit and navigate to HKLM\SOFTWARE\Aelita\Migration Manager\CurrentVersion\Exchange Data
For 64bit OS use the 32bit registry tree:
HKLM\SOFTWARE\Wow6432Node\Aelita\Migration Manager\CurrentVersion\Exchange Data
Create a new DWORD value called ShowAdditionalParameters and set it to 1.