Selective and group journaling enable you to configure simple filtering of journal mailbox messages. You can set up special filters, called "external filters", to define how specific messages are processed. For example, you may not want to archive system messages or Out of Office messages or you may want to identify messages sent from one group of users to another.

Custom filtering provides more sophisticated journal filtering with a wide variety of filtering rules that you can apply when archiving journal mailboxes.

See Exchange archiving filters

See Compliance Accelerator and Exchange journaling

See About Exchange Server archiving and user mailboxes