How to Archive Former Employees Mailboxes in Office 365 Without a License

Published By Mohit Kumar Jha

Approved By Admin

Published On July 15th, 2025

Reading Time 5 Minutes Reading

When an employee leaves the company, their Office 365 mailbox still contains valuable business data. That’s why I created this write-up to explain how to archive former employees’ mailboxes in Office 365 step by step.

Why You Should Archive Former Employees’ Mailboxes?

Here’s why I always make sure to archive mailboxes before deleting user accounts:

• Many organisations are required to retain communications for several years.
• Archived emails may be necessary for future litigation.
• Teams may need access to project-related emails after someone leaves.
• Archiving allows me to retain data without incurring the cost of an active license.

How to Archive Former Employees Mailboxes in Office 365 Step by Step

When an employee leaves, I don’t immediately delete their account. Instead, I follow these preparatory steps:

Note: To archive or convert a mailbox to an Inactive Mailbox, the mailbox must have existed with a license at some point.

• To preserve the contents after the mailbox is deactivated, I place the mailbox on Litigation Hold or In-Place Hold. Here’s how I do it:

• Open Microsoft Compliance and sign in as a global admin.
• Select the eDiscovery option and then Core.
• Create a new case or use an existing one.
• Now, under the case, select Hold > + Create, and name the hold.
• In choose Locations, select Exchange Mailboxes, and search for the user.
• Press the Next button, then Create. Alternatively, use Litigation Hold via PowerShell: Set-Mailbox “example@domain.com” -LitigationHoldEnabled $true

After placing the hold, you can safely delete the user account or remove the license. Microsoft will automatically convert the mailbox to an Inactive Mailbox. This is a key part of the process if you’re wondering how to archive former employees mailboxes in Office 365.

To delete the user:

• Open the Microsoft 365 Admin Center, and click on the Users and Active Users options.
• Select the user, and Delete.

If needed, retrieve data from the archived mailbox using Content Search in the Compliance Center:

1. Open Microsoft Compliance
2. Choose Content Search
3. Click New Search
4. Define search criteria
5. Under Locations, choose the Inactive Mailbox
6. Run and export the results as PST or review them online

If a manager or replacement employee needs access to the mailbox, grant Full Access to it before deleting the account:

Add-MailboxPermission -Identity “example@domain.com” -User “manager@exampledomain.com” -AccessRights FullAccess

Make sure to do this before deleting the user account.

How to Archive Former Employees Mailboxes in Office 365 (Two Automated Methods)

When I need to export Office 365 mailbox to PST, I rely on two main methods:

1. Using a professional tool
2. Using Microsoft’s built-in eDiscovery export via Microsoft Purview

The details of both of them are given below:

#Method 1. Tried & Tested Automated Solution

When I want a reliable way to export Office 365 mailboxes to PST, I use the SysTools Office 365 Exporter. It’s more efficient than manual methods and doesn’t require complex configurations. Additionally, it allows you to add filters to archive only relevant data.

The best thing is, before any commitment, you can try this for free. After downloading this, just follow the steps below to learn how to archive former employees mailboxes in Office 365:

• Step 1. Run the solution, and select Microsoft 365 & Outlook (PST) as the output file format. 

Note: You can export data in multiple file formats: MSG, EML, MBOX, PDF & PST.

• Step 2. Now, choose the data to archive, and leverage the Date Filter option if needed.

• Step 3. Provide the source Microsoft 365 credentials, and validate them.

• Step 4. Map the source users via Fetch Users, Import Users, or Download Template.

• Step 5. After validating permissions, press the Start Export button. 

This method is ideal when I’m exporting multiple mailboxes without affecting formatting.

#Method 2. Use eDiscovery

Sometimes, I use Microsoft’s built-in eDiscovery method through the Microsoft Purview Compliance Center to handle tasks like how to archive former employees mailboxes in Office 365. However, I found it’s more complex to configure. Here’s the process I follow:

1. Open Microsoft Purview Compliance Center, then click on Content Search
2. Create a new search and add the user’s mailbox
3. Define search criteria or export all mailbox content
4. Once the search is complete, click Export results
5. Use Microsoft’s eDiscovery Export Tool to download the PST file

Best Practices I Follow

Here are some points to remember:

• Always document which mailboxes are on hold and archived
• Review retention policies to avoid accidental deletion
• Periodically review Inactive Mailboxes and clean up if no longer required

How Long Are Inactive Mailboxes Retained?

According to the official Microsoft guide, the Inactive Mailbox will be retained as long as the hold is applied. If the hold is removed, the mailbox will be purged in 30 days.

Author’s Verdict

Archiving former employees’ mailboxes in Office 365 is a technical task. I’ve implemented this process across multiple organisations using the solutions I mentioned in this guide. I’m damn sure, now you have clear insight on how to archive former employees mailboxes in Office 365 effortlessly and quickly.