Email Journal Migration
Does Microsoft 365 provide email journaling?
The answer is no, not in a conventional sense!
A conventional journaling solution has two components:
- An agent or rule that intercepts messages in transit and directs a copy elsewhere, and
- A repository that stores each journaled message together with ‘envelope’ metadata (e.g., To, From, BCC, and the expanded members of any distribution lists at the time of sending).
Microsoft 365 actually only provides the first component – the journaling agent – which forwards copies of emails to a separate journal repository. This repository needs to be hosted elsewhere, for example:
- On an on-premises Exchange server (with or without an archive), or
- In a third-party cloud service such as that provided by Mimecast or Proofpoint.
Not long ago, if your organisation needed to journal email, there was no choice but to run a separate journaling service.
Today, Microsoft 365 has evolved to take on that role in different ways. Instead of maintaining a costly, complex standalone journal repository, most organisations now rely on Microsoft 365’s built-in retention and eDiscovery features to meet the same compliance requirements. The next section explains how this works in practice.
This is how Microsoft 365 replaces a conventional journal
Microsoft 365 achieves the same compliance outcomes as a traditional journal by retaining content at the mailbox level and making it available to the eDiscovery process.
Rather than storing copies in a separate journal mailbox, Microsoft 365 retains messages at the individual mailbox level. This is typically achieved by placing mailboxes on Litigation Hold or applying Microsoft 365 retention policies. As a result, all relevant sent and received email is retained for the duration of your retention requirements.
Other things Microsoft 365 does for emails you retain this way include:
Deleted emails remain discoverable
Even if a user deletes an email from their view, Microsoft 365 retains that item in a hidden area of the mailbox—the Recoverable Items folder—so it remains available to eDiscovery and is preserved according to your retention settings.
Critical ‘envelope’ information is preserved
Traditional journals capture data a recipient would not ordinarily see, such as BCC recipients and the members of expanded distribution lists. Microsoft 365 addresses this by ensuring BCC recipients are preserved in the sender’s mailbox and by expanding and storing distribution list membership in hidden headers at send time, so this information is discoverable.
Long term retention shouldn’t be a problem
A journal repository is usually single‑instanced: one stored copy plus metadata for many recipients. Microsoft 365 is multi‑instanced: each recipient’s mailbox contains its own copy. In practice, this does not create a storage problem because Exchange allocates an additional 100 GB quota for the Recoverable Items area, and the Mailbox Folder Assistant enforces your retention policies automatically. Inactive mailboxes (for leavers) can also be left on indefinite hold without additional license cost.
Migrating an existing journal to Microsoft 365
Many organisations have legacy journal archives (on‑premises or cloud). Because the journal model and the Microsoft 365 model differ, careful planning is essential. There are at least two viable approaches to handling historical journal data, each with different implications for long‑term management and eDiscovery. If you’re considering such a migration, seek guidance to ensure the imported data maintains its completeness and legal defensibility.
Next steps
If you’re evaluating how to retire a traditional journal and rely on Microsoft 365 instead, start by confirming your retention requirements, ensuring Litigation Hold or retention policies are applied consistently, and validating that BCC and distribution list expansion data is discoverable in test cases. For advice on migration options and implementation details, contact our migration team.
You can also explore our eBook for making Microsoft 365 a one‑stop shop for email records compliance.
