If you have been granted permission to access another user's mailbox, Outlook on the web makes it easy to view and manage their emails without signing in to a separate account. This is commonly used for shared inboxes, delegated mailboxes, and team email accounts where multiple people need access.

Open the Mailbox

Method 1: Open Another Mailbox in a New Browser Tab

1. Sign in to Outlook on the web
   Open your web browser and sign in using your Microsoft 365 work or school account.
2. Open your profile menu
   Select your profile picture or initials in the upper-right corner of Outlook.
3. Choose Open another mailbox
   Select Open another mailbox from the menu.
4. Enter the mailbox details
   Type the full email address or name of the mailbox you have permission to access.
5. Open the mailbox
   Select the correct mailbox from the search results, then click Open.
6. Work from the mailbox
   The mailbox opens in a new browser tab. Depending on your assigned permissions, you can read emails, move messages, manage folders, and send email from the mailbox.

Method 2: Add the Mailbox to Your Folder List

1. In the left navigation pane, right-click Folders or your mailbox name.
2. Select Add shared folder or mailbox.
3. Enter the shared mailbox email address.
4. Click Add.
5. The mailbox will appear in your folder list, allowing you to access it without opening a separate browser tab.

Tips for Working with Shared Mailboxes

• Pin the mailbox tab in your browser if you access it regularly.
• Use separate browser profiles to keep different work environments organized.
• Check mailbox folders and rules if expected emails are missing.
• Use Outlook's search filters to locate messages more quickly.
• Confirm that you have the appropriate sending permissions if you need to send email from the mailbox.

Common Checks

1. Verify your permissions
   Confirm that your Microsoft 365 administrator has granted your account access to the mailbox.
2. Check the mailbox address
   Make sure you entered the correct email address or mailbox name.
3. Sign out and sign back in
   If access was granted recently, sign out of Outlook on the web, then sign back in to refresh your permissions.
4. Refresh Outlook on the web
   Reload the page or reopen Outlook to see if the mailbox becomes available.

Additional Troubleshooting

1. Clear your browser cache and cookies
   Cached data can sometimes cause sign-in or loading issues.
2. Try another browser or a private browsing window
   This helps determine whether browser extensions or stored sessions are causing the problem.
3. Allow time for permission changes to sync
   New mailbox permissions may take some time to propagate across Microsoft 365.
4. Verify Send As or Send on Behalf permissions
   If you can open the mailbox but cannot send messages, you may need additional sending permissions.
5. Check mailbox storage limits
   A mailbox that is close to or over its storage quota may respond slowly or fail to update correctly. Your administrator can verify its status.
6. Contact Swazzy Support
   If the mailbox still cannot be opened or continues to display errors, contact Swazzy Support for further assistance.

• You can only open another mailbox if your account has been granted the required permissions.
• Your level of access depends on the permissions assigned. Some users can only read messages, while others can send mail, delete items, or manage folders.
• Changes made in the mailbox are applied immediately and are visible to other authorized users.
• If multi-factor authentication (MFA) is enabled, complete all required verification steps before attempting to access the mailbox.
• Shared mailboxes and delegated user mailboxes may behave differently depending on how permissions are configured.
• Always follow your organization's privacy, security, and data handling policies when accessing another person's mailbox.

Accessing another person's mailbox in Outlook on the web allows authorized users to manage shared communications efficiently while maintaining a single Microsoft 365 account. If you continue to experience access or permission issues after completing the steps above, contact Swazzy Support for further assistance.