Why use a shared mailbox in Microsoft 365?
Do you manage a generic address or need to keep emails from a former user? Discover why shared mailboxes in Microsoft 365 Outlook are the ideal solution for collaboration and security.
Benefits:
- Simplified collaboration
- Enhanced security
- Email traceability
- No extra cost (depending on mailbox size)
Prerequisites
- The shared mailbox must be created by someone with Microsoft 365 admin rights.
- You must have Full Access and Send As permissions.
- For transparency, the Copy sent emails option must be enabled by the admin.
🔍 What’s the difference between a shared mailbox and delegation?
Delegation allows you to grant access to your personal mailbox to someone else. A personal mailbox is always linked to a Microsoft 365 user account, unlike a shared mailbox which is independent of any user.
(For administrators) Creating and configuring in Microsoft 365
Before adding the mailbox in Outlook, it must be created in the Microsoft 365 Admin Center. Here’s how to configure it properly to avoid access issues:
- Go to Microsoft 365 Admin Center
- Navigate to Teams & Groups > Shared mailboxes > Add a shared mailbox
- Enter the name, email address, and aliases.
- In the shared mailbox list, click the new mailbox to view details on the right.
- In the Manage mailbox permissions section, click the following to add users who will have access:
- ✅ Read and manage permissions (also called Full Access)
- ✅ Send As permissions
- 🔲 Send on behalf permissions (optional)
Tip: What’s the difference between Send As and Send on behalf?
- Send As: Send an email as if you were the shared mailbox itself.
Use case: official communication on behalf of the company or department. - Send on behalf: Send an email on behalf of the shared mailbox, but your identity remains visible.
Use case: transparency (everyone knows who sent the message), useful for teams where personalization matters.
(For administrators) Copying sent messages to the shared mailbox
By default, emails sent from a shared mailbox are only visible in the sender’s personal mailbox. Enable this option to ensure transparency and collaborative tracking in Microsoft 365 Outlook.
- Still in the Microsoft 365 Admin Center , under the shared mailbox details:
- In the Sent Items section, click Edit and enable:
- ✅ Copy items sent as this mailbox
- 🔲 Copy items sent on behalf of this mailbox (optional)
- Still in the Microsoft 365 Admin Center , under the shared mailbox details:
Automatic addition of a shared mailbox in Outlook (Windows/Mac)
If your administrator has correctly configured permissions, the shared mailbox should automatically appear in your Microsoft 365 Outlook. Here’s what you need to know:
- Restart Outlook
- In the folder pane, the shared mailbox should appear under your main account
- If it still doesn’t appear after a few hours (and unfortunately this happens often), switch to the manual method.
⚠️ Note : Why doesn’t automatic addition always work? It can fail due to various reasons: partially compatible Outlook versions, old or corrupted profiles, or Exchange settings (AutoMapping not enabled).
Manual addition of a shared mailbox in Outlook (Windows/Mac)
The mailbox isn’t showing up? Don’t worry—here’s the manual method to add it quickly in the new Microsoft 365 Outlook:
- In the new Outlook, click File > Account Information
- Select your main account, then Manage
- If the mailbox isn’t listed, click Add and enter the shared mailbox address
- Restart Outlook if needed
Manual addition of a shared mailbox in Outlook Web (OWA)
Using Outlook Web? The process is identical to the new Outlook Desktop. Here’s how to add your shared mailbox for universal access in Microsoft 365:
- Sign in at https://outlook.office.com
- Click File > Account Information
- Select your main account, then Manage
- If the mailbox isn’t listed, click Add and enter the shared mailbox address
Need help configuring Outlook in Microsoft 365?
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