You only want to migrate the offline content stored locally on individual workstations. When attempting to do so, the online messages are being migrated as well and result is messages are being duplicated on the target Exchange server (Messages that have been deleted or moved are now showing in the original location)
Standard behavior for SSDM is to connect to GroupWise server and to migrate online messages as well. This is controlled by two INI settings below in qwdtapp.ini file, which are enabled (set to value 1) by default:
Changing those two settings to 0 (disabling them) as example below, tells SSDM to not migrate messages on GroupWise server:
When AppDoesMail=0, the behavior is the setting on MigrateServerMail will be ignored. So setting both to 0 might be redundant, although it has been a tested configuration that works for this situation.