For compliance archiving the journaling mechanism of Exchange is used (see chapter Compliance archive). This mechanism can lead to journal report duplicates, e.g. if the sender-/recipient-mailboxes are distributed on several exchange servers (or mailbox databases). These duplicates can even have different sender/recipient information, e.g. when each participating Exchange server (or mailbox database) can resolve another part of the members of a distribution group.
Using compliance single instancing allows referencing only one instance of the e-mail in ImageMaster, but each duplicate journal report will add its sender and recipient information to the metadata of the archived e-mail. In this case an e-mail is not split into body and attachments. Each e-mail with attachments is stored and referenced as a whole.
To enable this type of single instancing, select Compliance Single Instancing in the E-Mail configuration room of the AdminClient. See [UM AdminClient], chapter ImageMaster settings for details.
Compliance single instancing works within one ImageMaster document type.
Make sure to configure the policies’ ImageMaster server settings in such a manner that mailboxes whose e-mails should merge the journal sender-/recipient information use the same document type, and the other way round: that mailboxes whose e-mails should NOT refer to each other do NOT use the same document type.
In particular, do not use the same ImageMaster document type for mailbox archiving and compliance archiving!