Glossary
Journaling
An Exchange Online feature that captures copies of every email matching a rule for compliance archiving.
Journaling in Exchange Online is the feature that captures full copies of email messages matching a journaling rule, routing them to a designated journal target — typically a third-party compliance archive (Mimecast, Smarsh, Proofpoint, Veritas) or a journaling-specific mailbox. Used in regulated industries — financial services SEC/FINRA, healthcare HIPAA — for immutable archive retention beyond what Microsoft 365's native retention provides. Configured in the Exchange Admin Center → Compliance management → Journal rules, with scope by sender, recipient, or all messages. The journaled copy is independent of the sender / recipient mailboxes — deletion or tampering on either side doesn't affect it.