Microsoft shared mailbox in Apple Mail

Hi @Khairnar, Dhaval Ramesh

Thank you for posting your question in the Microsoft Q&A forum.  

I understand that you are considering to add your Microsoft shared mailbox in Apple Mail. 

Currently, I have not identified any official documentation or support article confirming that Apple Mail supports Microsoft 365/Exchange shared mailboxes using modern authentication (OAuth2/MFA) yet.

Based on my research, I found a thread, where users report that previously suggested methods, such as using IMAP workarounds or adding the shared mailbox as a separate Exchange account, no longer work, especially after Apple and Microsoft enforced modern authentication. 

You can refer via: Microsoft shared mailbox in Apple Mail? - Apple Community 

Note: Microsoft is providing this information as a convenience to you. These sites are not controlled by Microsoft, and Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please ensure that you fully understand the risks before using any suggestions from the above link. 

On the other hand, you could consider a workaround by downloading the Outlook for iOS app or using Outlook Web Access (OWA), where you can successfully add and access a shared mailbox through Outlook. 

Additionally, since you’re unable to use the shared mailbox in the iOS Mail application, and because the iOS Mail app is an Apple product, you could consider to contact Apple Support to see if they can provide better guidance or alternative solutions for this issue. 

Apologies for redirecting you to the related development team support, as forum moderators, we don’t have access to the systems required to troubleshoot this effectively. My role is focused strictly on Microsoft technologies, and I don’t have access to backend systems or resources needed to investigate third‑party implementations such as Apple Mail. 

Please feel free to correct me if I misunderstood your request. If you have any additional concerns, feel free to comment below. I would be more than happy to assist. 

Note: Please follow the steps in [our documentation] to enable e-mail notifications if you want to receive the related email notification for this thread. 

Apple Mail is not documented as supporting Microsoft 365/Exchange shared mailboxes directly, especially with modern auth and MFA. The available guidance instead covers:

1. Using Outlook for Mac to open shared mailboxes (recommended for Microsoft 365/Exchange shared mailboxes).
2. Using POP/IMAP in Apple Mail for basic mailbox access (not shared-mailbox–specific and may not support shared mailbox permissions or send-as scenarios).

For shared mailboxes on Mac, the supported approach is to use Outlook for Mac and add the shared mailbox there rather than Apple Mail.

To access a shared mailbox in Outlook for Mac when permissions are already granted:

1. Open Outlook for Mac.
2. Go to Tools → Accounts and select the primary account that has access to the shared mailbox.
3. Select Delegation and Sharing.
4. Open the Shared With Me tab.
5. Select + and add the shared or delegated mailbox.
6. Alternatively, use File → Open → Shared Mailbox.

If full access permissions are granted, another supported option in Outlook for Mac is:

1. Tools → Accounts → + → New Account.
2. Enter the shared mailbox email address.
3. Under Authentication, enter the primary user credentials (when Full Access is configured that way).

For Apple Mail specifically, the only documented configuration is standard POP/IMAP access to an individual mailbox (not a shared mailbox). This requires:

1. In Apple Mail, choose Mail → Add Account → Other Mail Account.
2. Enter name, email address, and password.
3. If automatic setup fails, choose Next and manually configure:
   • Account Type: IMAP or POP.
   • Incoming server: outlook.office365.com for Microsoft 365.
   • Outgoing server: smtp.office365.com for Microsoft 365.

However, this POP/IMAP method does not provide the shared mailbox behavior described for Exchange shared mailboxes (no automapping, delegate access model, or add-in support) and is not documented as a supported way to use shared mailboxes with MFA in Apple Mail.

For full shared mailbox functionality on macOS with MFA, Outlook for Mac is the supported client.

References:

• Open a shared Mail, Calendar or People folder in Outlook for Mac
• Set up email in Mac OS X Mail
• Implement shared folders and shared mailbox scenarios in an Outlook add-in