Restore Deleted Mailbox in Microsoft Office 365 Account Using This Guide

Written By Mohit Jha
Anuraag Singh
Approved By Anuraag Singh
Published On February 19th, 2024
Reading Time 6 Minutes Reading

You can be panicked when you realize that you have accidentally deleted your important emails from your Office 365 account. And, you are unable to restore those mail. So, if you have faced a similar situation, then read this article till the end. As, in this write-up, we are going to discuss the best possible way to answer the user query i.e. “how to restore a deleted mailbox in Office 365 after 30 days, or when the retention period expires.

Table of Content

Here is a real-life scenario where a user accidentally deleted his mailbox data. Let’s have a quick sneak peek into it.

Hey, I am the administrator of the company. I asked one of my Office 365 users to remove some emails which are not in use. But by mistake, he had deleted multiple mailboxes data from Office 365, and those mailbox contained more than 30000 emails. At least 80 percent of the emails are very important for work. Now, I am not able to restore them. I need help to recover soft deleted mailbox in Office 365. Although i have the PST files  but manual Import and Export taking days to recover those emails. If anyone has any solution, then let me know.”

What Happens When A Mail Gets Deleted From Office 365?

When a user deletes their mailbox data from Office 365 then, deleted mailbox data goes to the Deleted Items Folder.  Now,  how long does Office 365 keep emails deleted emails? The data resides in the Deleted Items Folder until the retention period expired which is of 30 days. After hitting the retention period, the data gets permanently deleted from the O365 account and then the deleted item recovery becomes almost impossible. But if you have the respective PST files for those accounts. then you can easily restore them using these ways.

How to Restore A Deleted User Mailbox in Microsoft Office 365?

If the mailbox was deleted by deleting the corresponding user account, then you can restore the mailbox by restoring the user account in the Microsoft 365 admin center.

PowerShell Command to Restore A O365 User Account

You can recover soft-deleted mailboxes using the PowerShell cmdlet below. The cmdlet example below restores the mailbox for Allie Bellew.

Connect to Exchange Online PowerShell

Run the below Undo-SoftDeletedMailbox cmdlet.

Undo-SoftDeletedMailbox [email protected] -WindowsLiveID [email protected] -Password (ConvertTo-SecureString -String ‘Pa$$word1’ -AsPlainText -Force)

Note: You can not restore or recover a user mailbox if that account is held for 30 days using this command or EAC.

How to Recover Deleted Office 365 Account After 30 Days?

If you want to get back the deleted mail data from Office 365 after the 30 days grace period, then you have to use a professional solution such as SysTools Office 365 Backup & Restore Software. This software is engineered to retrieve the deleted items to the Office 365 account from their respective .pst files.

Note:– The recovery process only works when you create a backup of your mailbox data at a regular time interval.

The tool is a complete package for backing up and restoring the Office 365 mailbox data items without any data loss. With the help of this software, the administrator is free to recover multiple PST files into the different mailbox(es) at once.

Must Read: How to Save Office 365 Emails to Desktop?

Why Using Tool Is A Good Way to Restore A Deleted Mailbox in Office 365?

The following lets you know how an automated solution is far better than a complex PowerShell method when comes to recovery of permanently deleted Office 365 mails.

  • Point-in Time-Restore Option – This software restores backed-up data from PST files to the user mailbox of the same or different Office 365 account. It includes data such as emails, calendars, contacts, etc.
  • Complete Office 365 Mailbox Backup – This software allows users to save single as well as multiple mailboxes of your Office 365 to the local system. Also when you want to create the offline backup of Office 365 data, this software allows you to choose any folder instead of an entire mailbox.
  • Folder Hierarchy Feature – This software is capable to maintain the folder hierarchy of the data after the data is moved from OWA to local storage. As well as, it provides the feature of Date Range which specify a specific set of date in the “From” and “To” field. After that, the tool will back up and restore data that lies between the mentioned date range only.
  • Functionality For Cross-User Restore – This functionality offers the admin to restore data of one Office 365 member to another user account. This data can be from deleted items folder and the rest of the folders. So, if any co-worker leaves the workplace and its account PST file resides in the system, then the admin can able to retrieve its data.
  • Date Filter – It allows you to backup and restores data selectively using its smart date filter. You can choose the required date range and the software will backup or restore only those data.

Must Read to Know: Does Microsoft Backup Office 365?

After understanding its mains features, let’s see the working process of the software:

Software Steps to Restore A Deleted Mailbox in Office 365

Step 1. Download and install the tool on your Windows system. After that, click on Restore.

Step 2. Select Outlook as source and Office 365 as destination platform.

Step 3. Chose the required Office 365 mailbox items such as email, contact, calendar, etc from the workload selection. 

Step 4. Now define the location, where you have stored the Outlook PST files on your computer.

Step 5. Now validate the required permissions.

Step 6. Input Office 365 credentials and Validate account permissions.

Step 7. Use any of these three options to fetch the Office 365 users’ accounts to restore them.

Note:- If you are an Admin and you want to restore multiple users’ accounts then, at this step you can download the CSV file containing the standard format. Provide the email ids of the users and the respective path for the PST files and upload them.

Step 8. Now, select the desired user account, validate the required permissions and lastly click on Restore.

Final Say On Recovering Deleted O365 Mailbox

In this article, we have discussed two ways to restore a deleted mailbox in Office 365. If you have to restore only a few accounts then you can easily configure them in Outlook and you can use the Export and Import feature to restore them or use can use the PowerShell commands.  But If you have multiple accounts to restore, and you have the PST files of your respective user mailboxes. Then you can easily restore them to Office 365 by using the above-mentioned software. 


By Mohit Jha

Mohit is a writer, researcher, and editor. Cyber ​​security and digital forensics are the two subjects that keep Mohit out of his seat. In addition, he hopes that the well-researched and thought-out articles he finds will help people learn.