Export Online Archive to PST: Export 100GB+ Mailbox Data Securely

Why Export Exchange Online Archive Mailbox?

• Local backup: Keep another copy of important archived emails.
• Migration: Move archived mailbox data to another environment.
• Legal requirements: Preserve mailbox information for investigation or review.
• Offline access: Open archived emails without connecting to Microsoft 365.
• Long-term storage: Store older emails on local or external storage.

Method 1: Export Online Archive to PST Using Outlook

If the Online Archive mailbox is visible in the Outlook desktop application. You can use Outlook’s Import/Export feature to export it.

1. Launch the Outlook desktop application connected to the Microsoft 365 account containing the Online Archive.
2. Look for a folder such as: In-Place Archive – [Mailbox Name] or a similar archive mailbox name.
3. Expand the archive and check whether the required folders and emails are available.
4. Go to: File → Open & Export → Import/Export. The exact menu names can vary depending on the Outlook version.
5. Choose: Export to a file and click Next. Click: Outlook Data File (.pst) and continue.
6. Select the Online Archive mailbox or the required archive folder.
7. If you want to include subfolders, enable the option to include subfolders.
8. Select where you want to save the PST file.
9. Choose a location with enough free storage because a large Online Archive can create a very large PST file.
10. Click Finish to begin the export. Outlook will create the PST file containing the selected archive data.

Limitations of Manual Online Archive Export to PST

• Large exports can take considerable time.
• Outlook must remain available during the process.
• Large PST files can become difficult to manage.
• Exporting multiple archive mailboxes manually takes time.
• The process depends on the archive being accessible through Outlook.
• Export failures can require starting or repeating the export.

Method 2: Export Online Archive Mailbox to PST Using eDiscovery

Microsoft 365 administrators can also use Microsoft’s compliance and eDiscovery for Law Firms.

1. Sign in to the Microsoft Purview portal using an account with the required permissions.
2. Create or open an appropriate eDiscovery case.
3. Configure the search for the required mailbox.
4. Specify the mailbox or users whose data needs to be collected.
5. Configure the search according to the available Microsoft 365 options and ensure the required mailbox data is included.
6. Review the collected data before exporting it.
7. This step is important when the export is being performed for legal or compliance purposes.
8. Use the available export option to download the collected mailbox data.

Limitations: The Microsoft 365 compliance route can involve:

• Additional permissions
• Compliance role configuration
• Search and collection setup
• Export configuration
• Large data processing
• Administrative knowledge

Method 3: Professional Tool to Export Online Archive to PST

To overcome all the limitations, use the reliable SysInfo Exchange Server to PST Export Tool. It works with Exchange Online, on-premises Exchange, and hybrid Exchange deployments. Exports Primary, Archive, Shared, and Public mailboxes without requiring Outlook. Offers several advanced features, such as Remove Duplicates, Date Filter, Free up server space, skip previously migrated items, split large PST files, and more. 

This utility runs on localhost to avoid synchronization errors and exports Office 365 Mailbox to PST over 100 GB+. Suitable for both technical and non-technical users. Also, you can download this tool on both Windows and Mac systems. Multiple licensing options, including a demo version (Used to test its features and functions). 

Simple Steps to Export Office 365 Archive Mailbox to PST

1. Download the software, click on Open Browser (Localhost).
2. Sign in using Single User OAuth or Client ID & Secret ID.
3. Choose Online Archive Mailbox Type to export. Use Mapping.
4. Select the mailbox folder and choose PST as the Saving Format.
5. Apply advanced features and filters as needed. Press Start Export.

How to Verify? After Export Exchange Archive Mailbox to PST

Creating a PST does not automatically mean that the export was successful. After exporting the Online Archive, open the PST in Outlook and check:

• Number of folders
• Number of emails
• Important dates
• Attachments
• Sent and received messages
• Custom folders
• Older archived messages
• You can also open several messages from different dates to confirm that the content and attachments are readable.

Conclusion

This blog explained the manual methods and a professional tool to export Online Archive to PST. For a single mailbox, Outlook may be enough when the archive is accessible through the desktop application. There are other Microsoft 365 compliance tools that one may use when exporting is concerned with compliance or eDiscovery. Where there are large Online Archives or many mailboxes, one may opt for software that will facilitate the process through features like filtering, batching, splitting, incrementing exports, and reports.

Frequently Asked Questions

About The Author:

Simran Bhatia

Simran Bhatia is a technical content writer engaged in writing clear, concise, and SEO-optimized content. With a background in computer science and a passion for writing, I thrive to deliver complex technical content in simple layman terms.