Use a Shared Mailbox or Shared Calendar in Outlook
Use a Shared Mailbox or Shared Calendar in Outlook
A shared mailbox lets a group monitor and send from an address such as info@company.com; it can also include a shared calendar. A shared calendar can instead belong to an individual who grants view, edit, or delegate access. These are different permission models, so identify which resource you need before troubleshooting.
Never sign in directly as a shared mailbox or ask for its password. Microsoft states that a shared mailbox is not designed for direct sign-in. Your Microsoft 365 administrator must create it and add you as a member, and may separately grant Send As or Send on Behalf rights.
Open a shared mailbox
After IT confirms membership, close and restart Outlook. Newly granted access can take a few minutes to appear.
New Outlook: In Mail, right-click your account name and choose Add shared folder or mailbox. Enter the shared address. It normally appears under Shared with me.
Classic Outlook: The mailbox often appears automatically. If it does not, choose File > Account Settings > Account Settings, select your account, then Change > More Settings > Advanced > Add. Enter the shared address, finish the dialogs, and restart Outlook.
Outlook on the web: Right-click Folders or your primary mailbox name and choose Add shared folder or mailbox, then enter the shared address.
To send from the mailbox, start a new message and show the From field if needed. Select the shared address; if it is absent, choose Other email address and enter it. Verify the From address before sending. If recipients see “on behalf of” when they should see only the shared address, or sending is denied, this is a permission issue for IT rather than a password problem.
Use the shared calendar
For a calendar attached to a shared mailbox, restart Outlook after membership is granted. Open Calendar and select the shared mailbox calendar. Members can generally create, view, and manage its appointments, and changes are visible to the group.
For a person's calendar, the owner controls access. Can edit allows viewing and changing events. Delegate also allows scheduling and responding to meetings on the owner's behalf; delegate access is for Microsoft 365 or Exchange Online work/school accounts and applies to the primary calendar. In new Outlook or Outlook on the web, the owner opens Calendar > Share Calendar, enters a colleague, chooses a permission level, and selects Share. Use the least access needed.
Private events normally hide details, but an owner can explicitly allow a delegate to view private events. Treat that choice carefully. In classic Outlook, broader private-item access can affect multiple Exchange folders, not only Calendar.
Common problems
- Mailbox never appears: confirm the exact address and that IT added your user, then restart Outlook and try web access.
- Can read but cannot send: membership alone may not include the required sending permission. Capture the error and contact IT.
- Calendar is read-only: the owner may have granted view access rather than edit/delegate access.
- Invitation was not accepted: open the sharing invitation and select Accept.
- Recent permission change is not visible: allow time, restart Outlook, and compare with Outlook on the web.
- Wrong From address: manually choose the shared address before sending; do not resend repeatedly.
Do not alter another person's permissions, share a mailbox externally, or add delegates beyond your authority. Mailbox creation and organization-wide permission assignment belong to administrators.
When to escalate
Contact your IT help desk for missing membership, Send As/Send on Behalf errors, external-sharing restrictions, access inherited from a site or group, or permissions that differ between web and desktop Outlook.
Provide the resource address, your account, requested action (read, edit calendar, Send As, or delegate), Outlook version, exact error, when access was granted, and whether it works on the web. Include the resource owner's approval if your process requires it, but never include passwords.