How to Create and Manage Inactive Mailbox in Microsoft 365?

Summary: In this blog, we have discussed step by step How to Create and manage inactive mailboxes using Microsoft 365 Compliance Center (Web Interface). We will use Microsoft retention to apply the hold on the mailbox. 

Microsoft 365 allows you to retain the content of deleted mailboxes. This feature is called inactive mailboxes. Inactive mailboxes allow you to retain former employees emails after they leave your organization. A mailbox becomes inactive when a litigation hold or a retention policy is applied to the mailbox before the corresponding user account is deleted. The content of an inactive mailbox is written for the duration of the hold that was placed on the mailbox before it was made inactive. This allows administrators, compliance offices and record managers to use content search to search and export the content of an inactive mailbox.

Inactive mailboxes can’t receive email and aren’t displayed in your organization’s shared address book or other lists. Making a mailbox inactive involves three steps:

Step 1- Place the mailbox on litigation hold or apply a retention policy to it.

Step 2 – Second, delete the mailbox or corresponding user account.

Step 3 – Recover deleted mailbox through content search.

Now let’s discuss the first step.

Step 1 – Place the mailbox on litigation hold or apply a retention policy to it.

After the mailbox is inactive, its contents are retained until the hold or retention policy is removed, so let’s see the steps to create and manage inactive mailbox and Microsoft 365. We need to access and log in to the Exchange admin center. You can access the admin centre using the URL

  • We will put the user mailbox under a litigation hold in the first step. In Exchange Admin Center, Click on the mailbox that you want to put under a litigation hold.
  • After clicking on the mailbox, you can click on manage litigation hold.
  • Now turn on litigation hold and specify how long mailbox items are held. You can specify the hold duration in days as per your requirement.
  • Now click on save. The whole setting may take up to 60 minutes to take effect. And that message we can see from below image.
  • After the mailbox is placed on hold, our retention policy is applied. The next step is to delete the mailbox. The best way to delete a mailbox is to delete the corresponding user account in Microsoft 365 admin center. Now let’s open a new tab and type URL https://dmin, and that will open the Microsoft 365 admin center.

Step 2 – Delete the mailbox or corresponding user account.

  • In Microsoft 365 admin center click on users and click on active users; select the user and click on delete user.
  • We can see the confirmation message that our user is deleted successfully.
  • Now let’s view a list of active mailboxes using the compliance center.
  • Click on information governance.
  • Now click on retention policies.
  • Now click on the inactive mailbox to display a list of inactive mailboxes.
  • Here you see the inactive mailbox information.
  • Now click on it. We can see user email address and inactive information since this timestamp is on litigation hold and the duration is mentioned here.

Step 3 – Recover deleted mailbox through content search.

We can access the content of the inactive mailbox by using the content search tool. When we search an inactive mailbox, we can create a keyword search query to search for specific items or retain the entire content of this inactive mailbox. We can preview the search results or export the search results to an Outlook data file or as individual email messages.

  • Now click on content to search.
  • Now click on new search.
  • Now enter a name and click on next.
  • Now click on choose user to select the user.
  • Search mailbox name. And here you can find user information.
  • Now click on check box and click on done and click on Next. Here we search all the items of mailbox. And now click on submit.
  • Now you can see new search has been created. Click on done.
  • Here we have a content search name inactive mailbox. Now, let’s click on it.
  • You can click on the review mailbox here; we can see the preview of that messages in an active mailbox.

Here we can see the messages from our inactive mailbox. Suppose you want to download that message at that time. You need to click on download the original item. Suppose you’re going to export the result. You need to click on actions select the export result.

Select the export option which suits you better here, and we have output options that what you want to export all items excluding ones that have unrecognized format are encrypted, or one index for other reasons all items, including ones that have unrecognized format encrypted or warrant index for other reason and the third one only items that have unrecognized format are encrypted or valid index or other reasons here you can select the output options as per your requirement.


I hope you like this article, and it’s able to solve your problem. Did you enjoy this article? You may also like How to Disable OWA for New Users?. Don’t forget to share this article.

Amit Singh

Amit Singh

I am a dynamic Tech Enthusiast, specializing in various Microsoft technologies, including Office 365, Exchange, PowerShell, and Active Directory. I loved to helped customers worldwide design, implement, migrate, and secure Exchange and Office 365 through various roles for different employers, and more recently, as an independent consultant.