Microsoft 365 (Outlook on the web | Outlook for Windows/Mac) - Send as or Send on-behalf of another account

There are times when you need to send a message either as a another account or on-behalf of another account. Before you proceed, make sure you understand what send as permissions or send on behalf permissions are.

This document assumes you have been granted send as or send on behalf permissions to another account.

Note: If you are linked to a service account, you are automatically provided "full mailbox" and "send as" permissions to the account. This means you can open up the mailbox and 'send as' that account.

Important: In order to send-as or send-on-behalf of an account via Outlook desktop client, the account must be visible in the Global Address List (GAL). Check visibility. If the account is hidden, you must make it visible. Office 365 service accounts are hidden by default within GAL.

Depending on the permissions you have, the recipient(s) will see one of the following formats when receiving the message:

  • Send as permissions: Your message will appear to have come from the user that granted you this permission.
  • Send on behalf of permissions: The "From" address in any message sent by you will indicate that the message was sent by you on behalf of the user that granted you this permission.

Outlook on the web

  1. Log into Microsoft 365 via Outlook on the web.
  2. Click New email button within the ribbon. A new message windows will appear in the reading pane.
  3. If "From" box option is not visible, click on the "Options" menu and place a check mark within "Show From" box.
  4. Click on "From" field.
  5. If the address you want to send as is listed within the drop down menu, select it. Otherwise, select "Other Email Address..." and paste the address of the account you want to 'send as' or 'send on behalf' of.
  6. Enter the desired values within all the other fields and send the email.

If you do not have the proper permissions, you will receive an email saying Your message did not reach some or all of the intended recipients, followed by the subject, date and time the message was sent and a list of recipients. If you believe you should have sending permissions, contact the owner of the account or your support staff.

Outlook for Windows

New Outlook

  1. Start Outlook.
  2. Click New email button within the ribbon. A new message windows will appear in the reading pane.
  3. If "From" box option is not visible, click on the "Options" menu and place a check mark within "Show From" box.
  4. Click on "From" field.
  5. If the address you want to send as is listed within the drop down menu, select it. Otherwise, select "Other Email Address..." and paste the address of the account you want to 'send as' or 'send on behalf' of.
  6. Enter the desired values within all the other fields and send the email.

Classic Outlook

Important: In order to send-as or send on behalf of an account via classic Outlook desktop client, the account must be visible in the Global Address List (GAL). You can verify the visibility of the account using these instructions: Microsoft 365 - Show or Hide Service Account within Global Address List. If the account is hidden, you must make it visible. Office 365 service accounts are hidden by default within GAL.

  1. Start Outlook.
  2. Click New email button within the ribbon. A new message windows will appear in the reading pane.
  3. If "From" box option is not visible, click on the "Options" menu and place a check mark within "Show From" box.
  4. Click on "From" field.
  5. If the address you want to send as is listed within the drop down menu, select it. Otherwise, select "Other Email Address..." and paste the address of the account you want to 'send as' or 'send on behalf' of.
  6. Enter the desired values within all the other fields and send the email.

If you do not have the proper permissions, you will receive an email saying Your message did not reach some or all of the intended recipients, followed by the subject, date and time the message was sent and a list of recipients. If you believe you should have sending permissions, contact the owner of the account or your support staff.

Outlook for Mac

    • Important: You must first be subscribed to the account before you can send a message from the account. In addition, to send-as or send-on-behalf of an account via Outlook for Mac desktop client, the account must be visible in the Global Address List (GAL). You can verify the visibility of the account using these instructions: Microsoft 365 - Show or Hide Service Account within Global Address List. If the account is hidden, you must make it visible. Office 365 service accounts are hidden by default within the GAL.

      1. Start Outlook.

      2. Create a new message or reply to an existing message.

      3. From within the "From:" select box, select the account you want to send from.

        Note: If the account does not show up in the list, you must first subscribe to the account.

      4. After you compose the message, send it.

        If you have "send as" permissions, the recipient(s) will see the message from the account you are sending as.

        If you have "send on behalf of" permissions, the recipient(s) will see the message from "your_account on behalf of from_account".

      Note: We recommend you send a test message to yourself to make sure you have the appropriate permissions. If you don't, the message will stay in your "Drafts" folder. If this occurs, verify that you have the appropriate permissions to the account you are attempting to send from.

See Also


Keywordsmicrosoft office365 o365 m365 microsoft 365 send as permissions granted delegate delegated grantee outlook on the web owa 2019 2016 proplus windows mac os macintosh office on behalf of service account linked netid sending emails delegates read write subscribe owner none contributor reviewer non-editing author publishing editor editor publishing author author custom availability only limited details full details editor delegate   Doc ID40879
OwnerO365 S.GroupMicrosoft 365
Created2014-06-07 21:37:45Updated2024-08-19 08:26:28
SitesDoIT Help Desk, Microsoft 365, Wisc Account Admin
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