As I wish to keep the backup of mail box can be done by replication or copying of any new doc from source db to backup db. But there are two drawback as below:
Backup with replication:
1. Any changes in the source doc will be replciated back to backup db and hence replace the exisiting doc.
Is it any way to do so any new doc will be replicated as a new doc in the backup.
Backup with copyign:
1. I have written an agent which is run to copy the new and modified doc in the source to backup db. But, as the agent treat all doc to be new doc when the agent is first enabled.