We had a situation where the GRP became corrupted. Upon checking the content, we observed that the content itself was intact; however, the GRP header contained incorrect information. We manually extracted the messages to EML format and re-imported them into the client's mailbox.

In contact with SM, we were informed that this problem occurred due to a backup (we use robocopy), and that it did not occur during the backup itself (it happened between backups) or through deduplication performed on the server (which only occurs on weekends during the early morning hours, and this GRP corruption occurred during the week).

Has anyone else experienced a similar situation?

We are using three versions older than the latest one available at this time.