Shared mailboxes in Microsoft 365 are widely used by organizations to manage common email addresses such as support@ , info@ , sales@ , or hr@ . A shared mailbox allows multiple users to read and send emails from a single mailbox without requiring a separate license (up to a certain size).

In this article, we will walk through:

What a shared mailbox is
When to use it
Step-by-step instructions to create a shared mailbox
How to add members and assign permissions
Key best practices and common scenarios

What Is a Shared Mailbox?

A shared mailbox is a mailbox that multiple users can access to:

Read incoming emails
Send emails using the shared email address
Collaborate on email conversations

Common Use Cases

Prerequisites

Before you begin, ensure:

You have Microsoft 365 Admin or Exchange Admin permissions
User accounts already exist for members you want to add
Microsoft 365 tenant is active

Step 1: Sign in to Microsoft 365 Admin Center

Go to https://admin.microsoft.com
Sign in using an admin account
From the left navigation menu, select Teams & groups
Click Shared mailboxes

Step 2: Create a Shared Mailbox

In Shared mailboxes, click Add a shared mailbox
Enter the following details:
- Name: Support Team
- Email address: support@yourdomain.com
Click Save changes

The shared mailbox will be created automatically without a license.

Step 3: Add Members to the Shared Mailbox

After creating the shared mailbox:

Click on the newly created shared mailbox
Under Members, click Edit
Select users who should have access
Click Save

These users can now:

Read incoming emails
Send emails as the shared mailbox (depending on permissions)

Step 4: Configure Send As and Send on Behalf Permissions

Send As Permission

Allows users to send emails that appear directly from the shared mailbox .

Send on Behalf Permission

Emails will show as:

User Name on behalf of Shared Mailbox

To Configure:

Open the shared mailbox
Navigate to Email delegation
Assign users under:
- Send as
- Send on behalf
Save changes

Step 5: Access Shared Mailbox in Outlook

Automatic Mapping (Recommended)

Shared mailbox automatically appears in Outlook for assigned users
No manual configuration needed

Manual Access (If Required)

Open Outlook
Go to Account Settings
Select your account → Change
Click More Settings
Under Advanced , add the shared mailbox

Licensing Information

Shared mailboxes do not require a license up to 50 GB
If mailbox size exceeds 50 GB, a license must be assigned
Shared mailboxes cannot log in directly

Best Practices

Use shared mailboxes instead of individual accounts for team emails
Assign only required permissions to users
Periodically review members and access
Use mailbox auditing for compliance
Avoid assigning licenses unless necessary

Conclusion

Shared mailboxes are a powerful and cost-effective feature in Microsoft 365 that help teams collaborate efficiently. With proper configuration of members and permissions, they streamline communication while maintaining security and control.

By following the steps outlined in this article, you can confidently create and manage shared mailboxes in your organization.

How to Create a Shared Mailbox in Microsoft 365 Admin Center and Add Members