Send Emails from Another Mailbox in Outlook

Send Emails from Another Mailbox in Outlook

Sending emails from another mailbox in Outlook lets authorised users communicate from a shared mailbox, delegated account, or team inbox without signing in to a separate account. This is commonly used by support teams, reception staff, managers, and assistants who manage multiple mailboxes. Once the appropriate permissions are in place, you can send messages directly from the required mailbox.

Send an Email from Another Mailbox

Method 1: Outlook on the Web

  1. Sign in to Outlook on the web using your Microsoft 365 work or school
  2. Select New mail to create a new message.
  3. If the From field is not visible, select Options > Show From.
  4. Select the From button, then choose Other email address.
  5. Enter the shared or delegated mailbox email address.
  6. Add the recipient, subject, and message.
  7. Select Send.

Method 2: Outlook Desktop App (Windows and Mac)

  1. Open the Outlook desktop application.
  2. Select New Email to create a new message.
  3. If the From field is hidden, select Options > From.
  4. Select From, then choose Other Email Address, or select the shared mailbox if it appears in the list.
  5. Enter the mailbox email address if prompted.
  6. Add the recipient, subject, and email content
  7. Select Send.

Method 3: Set a Default From Address (Optional)

  1. Open a new email message in Outlook.
  2. Select the From drop-down menu
  3. Choose the mailbox you use most frequently
  4. Depending on your Outlook version and account settings, Outlook may automatically use this mailbox the next time you compose a message.

Resolve Mailbox Sending Problems

Basic Checks

  1. Confirm that you have permission to send from the mailbox.
  2. Verify that the correct mailbox appears in the From field before sending.
  3. Restart Outlook and try sending the message again.
  4. If access was granted recently, wait a few minutes for the permissions to synchronise across Microsoft 365.

Additional Troubleshooting

  1. Confirm whether you have Send As or Send on Behalf permissions
  2. Remove and re-add the mailbox from the From address list
  3. Try sending the message from Outlook on the web to determine whether the issue is limited to the desktop application.
  4. Sign out of Outlook, then sign back in to refresh your account permissions.
  5. Ask your Microsoft 365 administrator to verify mailbox delegation settings.
  6. Check whether cached Outlook profile or outdated credentials are causing synchronisation issues.

Important Things to Know

  • You must be granted permission before you can send from another mailbox.
  • Organisations may use either Send As or Send on Behalf permissions.
  • The sender information recipients see depends on the permission type assigned to you.
  • Permission changes can take time to synchronise across Outlook and connected devices.
  • Always verify the From address before sending important messages.
  • Sent messages may be stored in either the shared mailbox Sent Items folder or your personal Sent Items folder, depending on your organisation's configuration.

Frequently Asked Questions

Why can't I send from another mailbox in Outlook?
You may not have the required permissions, or Outlook may still be synchronising recently assigned mailbox access.
What is the difference between Send As and Send on Behalf?
Send As displays the shared mailbox as the sender, while Send on Behalf indicates that you sent the message on behalf of the mailbox.
Why is the From field missing?
The From field is often hidden by default. Enable it from the message options before composing your email.
Can I send from a shared mailbox using the Outlook mobile app?
Some versions of the Outlook mobile app support shared mailboxes, but available features may vary by device and app version.
Where are sent emails stored?
Sent messages may be saved in the shared mailbox Sent Items folder or your personal Sent Items folder, depending on your organisation's configuration.

Send with Confidence

Once the correct permissions have been assigned, sending email from another mailbox is as simple as selecting the appropriate From address when composing your message. If you're still unable to send from the mailbox after completing the steps above, please contact Swazzy Support for further assistance.

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