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PST Enterprise and Deduplication

  • Type: Knowledgebase
  • Date changed: 3 years ago
Solution #00007402


PST Enterprise, v3.2 or later


PST Enterprise v3.2 or later supports deduplication when migrating messages to the PST owner's Exchange primary or archive mailbox.
This deduplication only applies to IPM.Note and IPM.Post message classes. During migration, PST Enterprise:

1. Compares the message?s 'PR_SEARCH_KEY' property value with that of all the messages in the destination folder in the mailbox.

2. Deduplication only occurs for duplicate messages within the same folder, not for duplicate messages in elsewhere in the mailbox.

3. 'PR_SEARCH_KEY' is a property which contains an Exchange identifier which is unique to the message, but will not change if the message is copied or modified. This means that, for example, two messages which were created at different times but with identical subjects will not be considered duplicates as they will have different 'PR_SEARCH_KEY' values.If another message is found with the same 'PR_SEARCH_KEY' value, all the following properties are then compared:

4. Subject

5. Body text

6. Importance

7. Last verb applied e.g.replied/forwarded) and its time

8. Read/unread status

9. Code page (character set)

10. Categories

11. The binary content of any attachments

12. For any embedded messages, the same algorithm applies to them.If all the above properties are identical then the message is considered a duplicate and deleted, rather than migrated. If any of the above properties differ, the message will be considered as unique and migrated.

13. In the audit CSV this will be reported as "Message compared to user's mailbox, found to be duplicate so deleted".

14. In the Last Status Update in the administration website, this will be reported as e.g. "Migrated 9 messages out of 15 that matched from 15 found. 6 messages deleted due to being duplicate".