Journal mailbox is used by organizations to store copies of email messages for auditing, legal, and regulatory purposes. Users can store their email records in a journal mailbox over a long time. But there comes a time when they have to move this mailbox to Office 365, or now known as Microsoft 365. Therefore, I will help you explain how you can migrate Journal Mailbox to Office 365 within simple steps.

Table of Contents
  1. Problems when Transferring Journal Archives to Office 365
  2. Scenario 1: Migrate to Individual User Archive Mailboxes
  3. Scenario 2: Migrate to Centralized Compliance or Discovery Mailbox
  4. Data Growth During Migration
  5. Issues during Journal Mailbox to Microsoft 365 Migration Process
  6. Post De-Journaling Procedure
  7. Concluding Words

Most organizations want to migrate their legacy email archives from on-premises into Microsoft 365. In the email archives, you can find individual user mailbox archives, journal archives, and a combination of both archive types. Needing to transfer the complete journal mailbox in Microsoft 365 can be for several reasons.

Problems when Transferring Journal Archives to Office 365

  • Office 365 does not use the traditional single-interface journal archive model.
  • Usually, Microsoft 365 follows a user-centric mailbox structure where each mailbox contains the data belonging to a specific user.
  • Journal mailbox data cannot be imported into one mailbox. That’s why you have to migrate your data.
  • You must map the archived journal messages to the correct users.

It is not a great idea to directly migrate your raw emails from Journal to Office 365. As users will not be able to read them. However, if you de-journal them, your messages will be easily indexed, searched, and preserved in Office 365. But the process is not easy. The steps will be different based on your situation. Here, I will explain two common de-journal scenarios.

Scenario 1: Migrate to Individual User Archive Mailboxes

In this, you unpack the journal mailbox and put the mailbox into the actual archive mailbox of the users who originally sent or received them. Here are the steps that you must follow.

  1. First of all, map your SMTP addresses in your old Journal envelope to the active user in Office 365.
    1. For this, export the list of all active mailboxes and aliases from Microsoft 365.
    2. With this list, create a Migration Mapping File (a CSV file) that links on-premise email addresses to your current Microsoft 365 accounts.
  2. The data must be in the user’s archive mailbox so that they don’t interfere with your daily work.
    1. In the Exchange Admin Center, click the Recipients button.
    2. Select Mailboxes and your users. Hit the Enable Archive button.
    3. You can either run this PowerShell command: Get-Mailbox -ResultSize Unlimited -Filter {ArchiveStatus -eq “None”} | Enable-Mailbox -Archive
  3. Apply Litigation Hold or Purview Retention Policy to target all users’ mailboxes before you start the de-journaling process. This is because you are moving the compliance emails that you make sure do not delete them once you move to Office 365.
  4. Microsoft 365 does not provide a native De-Journaling API or any built-in tool to unpack journal envelopes. But you can use features like PST exports, Outlook Client rules, or specialized custom PowerShell scripts.

Scenario 2: Migrate to Centralized Compliance or Discovery Mailbox

Here, you keep all journaled data in one or many centralized hidden mailboxes that only legal or HR teams can use.

  1. Create a target Discovery mailbox in Office 365.
    1. Connect with Exchange Online PowerShell and use this command to create a new Discovery mailbox. New-Mailbox -Name “CentralizedJournalArchive” -Discovery
  2. After that, assign the permissions to this mailbox for access by your compliance officers.
    1. In the Microsoft Purview compliance portal, assign the appropriate users to the eDiscovery Manager role group.
  3. After that, you can migrate your Journal Mailbox to Office 365 by following these steps.
    1. First, I am going to export source Journal emails to a PST file. Open your Exchange Management Shell on your on-premise server.
    2. Run this command to export your mailbox New-MailboxExportRequest -Mailbox “OnPremJournalMailbox” -FilePath “\\Server01\PSTShare\JournalExport.pst”
    3. Wait for completed status displays to complete other steps.
  4. To import the exported journal PST file into your Office 365, install AzCopy and retrieve the Azure SAS URL.
    1. In the Microsoft Purview Compliance Portal, under Data Lifecycle Management.
    2. Click on Microsoft 365 and then Import.
    3. Hit New import job, add name, and choose Upload your data.
    4. Press the Show network upload SAS URL. Then, copy the unique URL that is created.
    5. Download and extract the latest version of the native AzCopy command tool to your local server.
  5. Use this command to upload a PST file using AzCopy: azcopy.exe copy “\\Server01\PSTShare\JournalExport.pst” “YOUR_COPIED_SAS_URL” –recursive
  6. After that, you have to tell Office 365 where your mailbox should receive. First, download the CSV template and fill out these details.
    1. Workload: Exchange
    2. FilePath: you can leave it blank unless you have uploaded the PST file in subfolder of Azure.
    3. Name: JournalExport.pst or your actual file name
    4. Mailbox: the target Office 365 discovery mailbox that you have created.
    5. IsArchive: False
    6. TargetRootFolder: /
  7. Go back to the import window in Microsoft Purview Portal.
  8. Check both boxes that you have uploaded your files and prepare your mapping document. Press Next.
  9. Upload your mapping CSV file and then validate.
  10. After that, click Save and select Import to Microsoft 365 to complete the final phase.

Data Growth During Migration

The Journal Mailbox only stores one copy of an email, regardless of how many recipients received it. So, while you migrate your journal Mailbox to Office 365, the size of your data is dramatically increased during the process. This is an important point for the organization as it can create issues in your planning.

  • 1 TB journal mailbox may lead to several TBs after de-journaling.
  • The messages that go to distribution groups can multiply storage space significantly.
  • Each mailbox copy duplicated your attachments.

So, you must know the storage growth and make sure you have sufficient storage space during the process.

Issues during Journal Mailbox to Microsoft 365 Migration Process

The process is difficult for several users, especially during the de-journaling method. The following are the common challenges many experience.

  • The Journal archive save their messages, which are different from the user mailbox. So, there can be any inaccuracies when you are assigned to the wrong mailbox.
  • The de-journaling process is technically difficult and time-consuming.
  • It can also increase your storage usage during the migration process.
  • You may fail to preserve the information, which will further affect future audits, investigations, and eDiscovery searches.
  • For the organization, there can be unexpected costs like additional Microsoft 365 storage, high licensing plans, etc., that impact our migration budgets.

Post De-Journaling Procedure

After you have de-journaled and sorted out the individual user mailboxes. Now, you need an efficient way to move your mailboxes to your Microsoft 365. So, try SysTools IMAP Migration Tool, a specialized software that can help you transfer your data using IMAP-enabled email systems.

Concluding Words

When it comes to moving your Journal Mailbox to Office 365, you have to be very careful, as you are moving your journal archive to your cloud platform. In this, I have explained the de-journaling method for two scenarios. Here, I also explain the growth data situation during the procedure and the challenges several users face. Now, after de-journaling using the software mentioned above to easily move your emails.