Exchange Online

How to Find the Licensed Shared Mailbox in M365

Monitoring an Exchange Online shared mailbox is essential for maintaining security, compliance, and smooth workflow management. Licensed shared mailboxes require special attention due to increased storage limits and the ability to enable advanced features like litigation hold. This guide helps to identify licensed shared mailboxes in Microsoft 365, monitor their usage, track storage, set alerts, and audit activity for compliance.

Using PowerShell Script

Microsoft 365 Permission Required

Exchange Recipient Reader + Directory Reader Least Privilege

Global Admin Most Privilege

Retrieving a comprehensive report of licensed shared mailboxes in Microsoft 365 involves multiple steps. This is because mailbox data is managed in Exchange Online, while licensing details are handled in Microsoft Online.
To simplify the task, we have created a dedicated PowerShell script to gather mailbox details from Exchange Online. It then cross-references the data with license assignments in MSOL and exports a detailed report in CSV format.
Download and run the following script in the Administrator PowerShell.

FindLicensedSharedMailboxes.ps1

Using M365 admin center

Microsoft 365 Permission Required

Exchange Recipient Reader + Directory Reader Least Privilege

Global Admin Most Privilege

Log in to the Microsoft 365 admin center.
Navigate to the Active Users section under Users tab and select the Licensed users view from the Filter icon.
The page will now list all the licensed users from your organization.
Now, search for the desired shared mailboxes. If they are licensed, they will show up in the results.

Note: Use this method only when checking if a specific shared mailbox is licensed. For larger datasets, make use of PowerShell method, as it is more efficient and time-saving.

Using AdminDroid
Simple & Quick

AdminDroid Permission Required Delegated

Any user with report access assigned by the Super Admin.

Log in to the AdminDroid Office 365 reporter.
Navigate to Licensed Shared Mailboxes report under Reports»Exchange»Shared Mailbox Info.
You can see the list of all shared mailboxes that have been assigned with a license.

AdminDroid Shared Mailbox Reporter

Say goodbye to lengthy PowerShell scripts to view Exchange Online shared mailbox with licenses!

The AdminDroid Exchange Online management tool provides a comprehensive solution for managing shared mailboxes. It provides detailed reports on both licensed and unlicensed shared mailboxes, helping you streamline management and optimize resource allocation effectively.

Manage the Shared Mailboxes with Ease Through Exports

You can export reports on licensed shared mailboxes in your preferred format, such as CSV, HTML, PDF, etc., to effectively track and manage them within your organization.

Automated Report Creation and Scheduling

AdminDroid’s scheduling functionality periodically sends a summary of newly created shared mailboxes directly to the desired inbox daily, weekly or monthly to ensure clear oversight and management.

Customizable Columns and Rich Filtering Options for User Data

Utilize AdminDroid's advanced column customization to achieve precise data tracking with detailed options such as mailbox size, license status, quota, type, and more.

Receive Alerts for Every Shared Mailbox License Revocation Activity

Get instant alerts on every shared mailbox license revocation with AdminDroid to quickly detect unauthorized changes and improve security.

Visualize Shared Mailbox Counts by Access Rights with AI-Powered Charts

AdminDroid's AI charts provide valuable visualizations of shared mailboxes by access rights, showcasing permission distribution. This enhances security by clearly highlighting access levels and potential risks.

Explore the Quick View to Easily Assess the Mailbox Sizes

AdminDroid's enhanced reporting functionalities lets you click any cell to open a quick view. For example, clicking the shared mailbox column shows the mailbox size for all users.

In conclusion, managing shared mailbox licensing ensures smooth communication, security, and productivity in Exchange Online. Regular license checks help prevent disruptions, maintain compliance, and enable features like increased storage and archiving.

Explore a full range of reporting options

Download Live Demo

Important Tips

Regularly review Exchange Online shared mailboxes' size to ensure they remain within the storage limits to prevent service disruptions.

Monitor the shared mailboxes' permissions to avoid unauthorized access and to protect sensitive information in Microsoft 365.

For shared mailboxes that require large storage, assign licenses (e.g., Exchange Online Plan 2) to enable auto-expanding archiving.

Common Errors and Resolution Steps

The following are possible errors and troubleshooting hints while dealing with shared mailboxes in Microsoft Exchange Online.

Error .\FindLicensedSharedMailboxes.ps1 cannot be loaded because running scripts is disabled on this system

This error occurs when trying to run the script in PowerShell. The execution policy is set to strict by default to prevent scripts from running.

Fix To resolve this error, you can set the execution policy using the below cmdlet and then run the script.

Replace <policy type> with RemoteSigned, if you want to allow locally created scripts to run without restrictions while requiring downloaded scripts to be signed for security.

Replace <policy type> with Unrestricted only for trusted environments or temporary troubleshooting, as it allows all scripts to run with minimal restrictions.

Set-ExecutionPolicy -ExecutionPolicy <policytype>

Error WARNING: Couldn't convert the mailbox

This error occurs when you attempt to convert the already converted shared mailbox in your organization.

Fix Check the mailbox type detail using the below cmdlet before converting an user mailbox into a shared mailbox.

Get-Mailbox -Identity <SharedMailboxIdentity>  | Select RecipientTypeDetails

Error PowerShell command returns details only for your mailbox

This error occurs when you don’t have sufficient permission to read the mailboxes in Exchange Online.

Fix Contact your global administrator to assign appropriate permissions.

Exchange Online

Frequently Asked Questions

Ensure Compliance and Optimal Storage with Licensed Shared Mailboxes

How do you track storage usage of a licensed shared mailbox?

You can track storage usage and limits for licensed shared mailboxes in Microsoft 365 using the admin center or PowerShell. Monitoring the shared mailbox size is important, especially if it’s approaching storage limits or if compliance policies are enabled.

Track Shared Mailbox Storage Using Exchange Admin Center

Login to your Exchange admin center with your admin credentials and click on Recipients»Mailboxes.
Filter the shared mailboxes using the Filter icon and select the desired shared mailbox which you want to check.
Under the General tab, go to the Mailbox Usage section. Here, you will see the current total mailbox size and percentage of used storage.

Check Shared Mailbox Storage Capacity Using PowerShell

To get more detailed and bulk reporting on shared mailbox storage, PowerShell is an efficient option.

Run the below cmdlet to connect to the Exchange Online PowerShell module.
```
Connect-ExchangeOnline
```

Retrieve storage information for all shared mailboxes by executing the cmdlet below.

Get-Mailbox -RecipientTypeDetails SharedMailbox -ResultSize Unlimited | Get-MailboxStatistics | Select DisplayName, TotalItemSize, ItemCount

This command lists the total storage size and item count for all shared mailboxes.

While the admin center and PowerShell are effective, AdminDroid offers an even more streamlined and feature-rich solution for monitoring shared mailbox storage over time.

One of the standout reports in AdminDroid is the Shared Mailbox Size Over Time report. This feature allows you to not only view the current size but also track the growth of shared mailboxes over a period. This visibility helps administrators plan for future storage needs, identify any unusual activity, and stay ahead of compliance requirements.

How does licensing affect shared mailbox retention policies in Exchange Online?

Shared mailboxes can operate without a license in Microsoft 365, allowing basic usage like email storage and access by multiple users. However, advanced features such as retention policies, archiving, and compliance-related functionalities require a licensed shared mailbox in Exchange Online. Without a license, the mailbox may be subjected to default tenant-wide retention settings and limited compliance capabilities.

Impact of Licensing Shared Mailbox on Retention Policies

Licensing fundamentally determines the compliance and retention features available for shared mailboxes in Microsoft 365. Below is a detailed breakdown of the effects:

Without a License:

Basic Retention Settings: Shared mailboxes rely on tenant-wide default retention settings, which are typically limited to basic configurations.
No Advanced Compliance Features: Litigation Hold, granular retention policies, or advanced archiving options are unavailable.
Risk of Data Loss: If users delete items, there is no assurance of preservation unless the mailbox inherits broader organizational compliance rules.

With a License:

Assigning a license, such as Exchange Online Plan 2, unlocks advanced compliance and retention features, including:

Enhanced Retention Management: Tailored retention policies can be applied to meet organizational or regulatory requirements.
Litigation Hold: Ensures preservation of emails even when deleted, enabling legal hold compliance.
Unlimited Archiving: Auto-expanding archiving helps manage growing data volumes while meeting retention mandates.

By assigning a license, organizations enhance their ability to manage retention policies effectively, reducing risks of non-compliance and ensuring data integrity.

How to enable shared mailbox archiving in Microsoft 365?

To enable archiving and compliance for a shared mailbox in Microsoft 365, assign it a license like Exchange Online Plan 2. Once a license is assigned, you can easily enable archiving and apply compliance features such as Litigation Hold and In-Place Hold using PowerShell.

Here’s how to enable archiving for a shared mailbox using PowerShell.

Run the below cmdlet to connect to the Exchange Online PowerShell module.
```
Connect-ExchangeOnline
```
Now, execute the following cmdlet to enable archiving for a desired shared mailbox.
```
Enable-Mailbox -Identity <SharedMailboxIdentity> -Archive 
```
Replace <SharedMailboxIdentity> with the actual email address of the desired shared mailbox.

An archive mailbox is created for the shared mailbox, moving older emails to the archive to manage storage.

AdminDroid offers detailed reports on archived shared mailboxes. These include metrics such as archive quota, limits, mailbox size, etc. In addition, the intuitive dashboard ensures effective storage and compliance management!

What happens to a shared mailbox if a license is removed after it exceeds the storage limit?

If a shared mailbox exceeds its storage limit and the assigned license is removed, several restrictions and issues will occur as listed below.

1. Email Reception Blocked Due to Storage Limit

If the shared mailbox surpasses the 50 GB limit and the license is removed, the mailbox will no longer be able to receive new emails.
Senders attempting to send emails to the shared mailbox will receive bounce-back notifications stating that the mailbox is full. Sending emails may also be restricted shortly after the limit is exceeded.

2. Limited Sending Capabilities Over Time

While users may still send emails temporarily even after a mailbox exceeds its storage limit, this functionality is only available for a limited time.
Once the mailbox continues to remain over the storage threshold, the ability to send new emails will eventually be disabled, impacting communication workflows.

3. Disabled Archive Mailboxes

Any auto-expanding archive mailbox or In-Place Archive that was available with the license will be disabled.
Users will no longer be able to store older messages in the archive, and existing archived data will remain inaccessible.

4. Compliance Features Disabled

Important compliance features like Litigation Hold, In-Place Hold, and eDiscovery will be disabled when the license is removed.
This can risk data retention, as the mailbox will no longer preserve items protected by these holds.

5. Manual Storage Management Needed

Without a license, there will be no way to increase the storage or enable archiving features.
Admins will need to manually reduce the mailbox size by deleting old or unnecessary emails to bring the mailbox back under the 50 GB limit.

In summary, removing a license from a shared mailbox that has exceeded its storage limit causes several issues. The mailbox won’t receive new emails, compliance and archiving features will be disabled, and manual storage management will be needed to restore functionality.