📖 What is Shared Mailbox?
Shared Mailbox is a specialized mailbox in Exchange Online that multiple users can access to monitor and send email from a common address. It does not require a separate license if it remains under 50GB and is accessed by licensed users.
"Student, remember that a Shared Mailbox doesn't need a license unless it exceeds 50GB or requires its own Exchange Online Archiving mailbox."
📚 Certification: Microsoft 365 Administrator (MS-102)
🔑 What are the Key Concepts of Shared Mailbox?
- ▸ Permissions are managed via Full Access for reading and organizing, and Send As or Send on Behalf for responding to external senders.
- ▸ Licensing is free for mailboxes under 50GB, but an Exchange Online Plan 2 license is required for storage up to 100GB.
- ▸ Shared mailboxes are disabled user accounts, meaning they cannot be used for direct login; users access them via their own licensed accounts.
- ▸ They differ from distribution groups because they store actual messages in a mailbox rather than just routing emails to member inboxes.
🎯 How does Shared Mailbox appear on the MS-102 Exam?
You may be asked to recommend a solution for a team that needs a central email address to track and respond to customer inquiries collectively, ensuring multiple members can see which emails have been handled.
A scenario might describe a shared mailbox that has reached its 50GB limit and is no longer receiving mail, requiring you to determine the correct license to assign to increase storage capacity.
Expect questions asking you to distinguish between a Distribution Group and a Shared Mailbox when a company needs to store and archive incoming communications for audit purposes rather than just routing them.
❓ Frequently Asked Questions
What is the practical difference between 'Send As' and 'Send on Behalf' permissions?
'Send As' allows a user to send mail that appears to come directly from the shared mailbox address. 'Send on Behalf' explicitly shows that the user sent the message on behalf of the shared address.
Can I assign a password to a shared mailbox to let an external contractor log in directly?
No, shared mailboxes are disabled accounts. To provide access, you must create a licensed user account for the contractor and then grant that account the necessary permissions to the shared mailbox.