You may need to send an email that appears to come from a colleague or manager, such as when covering for someone on leave. This is done using the Send on Behalf permission in Outlook. This feature allows you to compose and send messages from another person’s mailbox while clearly indicating you sent it for them. This article explains how to set up and use this permission correctly.
Key Takeaways: Sending on Behalf of Another User
- Delegate Permissions in Account Settings: The primary account holder must grant you Send on Behalf permission before you can use this feature.
- From Button in New Email: Click this button in a new message window to select the other user’s address as the sender.
- Sent Items Folder Behavior: Messages you send on behalf of someone else are saved in your Sent Items folder by default, not theirs.
Understanding Send on Behalf Permissions
The Send on Behalf feature is part of Outlook’s delegation system. It is different from having full access to a mailbox or using Send As permission. When you send on behalf of another user, the recipient sees “Sent on behalf of [User Name] by [Your Name]” in the message header. This provides transparency about who actually sent the email.
To use this feature, you must work in a Microsoft 365 or Exchange Server environment. The permission must be granted by the mailbox owner or an administrator. You cannot configure this yourself without the other person’s cooperation. Once granted, you add their mailbox to your Outlook profile to select it as the From address.
Prerequisites for Setup
Before starting, ensure the mailbox owner is ready to grant you permission. You will need their full email address. Your Outlook must be connected to a Microsoft Exchange account. This feature does not work with standard POP3 or IMAP accounts. Both you and the other user should have stable network connectivity during the setup process.
Steps to Configure and Send on Behalf
The process involves two main parts. First, the mailbox owner grants you permission. Second, you add their mailbox to your Outlook and send an email.
Part 1: Granting Permission (Mailbox Owner’s Steps)
The person whose mailbox you will use must complete these steps in the Outlook desktop application.
- Open the Delegation Settings
Go to File > Account Settings > Delegate Access. Click the Add button. - Select the Delegate User
In the Global Address List, find and select your name. Click Add and then OK. - Set the Permission Level
In the Delegate Permissions dialog, find the Calendar and Tasks sections. For the permission to send email, set the Inbox permission level to None. This is correct for Send on Behalf. Ensure the checkbox for Automatically send a message to delegate summarizing these permissions is selected. Click OK to save.
Part 2: Sending an Email as a Delegate (Your Steps)
After the permission is granted, you need to add the other mailbox to your profile and send the email.
- Add the Other Mailbox to Your Profile
Go to File > Account Settings > Account Settings. Select your email account and click Change. Click More Settings, then go to the Advanced tab. Click Add and enter the full email address of the person granting you permission. Click OK, then Next and Finish to close the windows. - Compose a New Email
Click New Email to open a message window. If the From field is not visible, go to the Options tab and click From in the Show Fields group to display it. - Select the From Address
Click the From button. A dialog box will appear. Click Other Email Address. Type or select the email address of the person you are representing. Click OK. - Send the Message
Compose your email as normal. When you click Send, the message will be delivered showing it was sent on behalf of the other user.
Common Mistakes and Limitations
Users often encounter specific issues when setting up or using Send on Behalf permissions. Knowing these can help you avoid problems.
From Field is Missing or Grayed Out
If you cannot see or click the From button, the mailbox may not be added correctly to your profile. Verify you completed the steps in File > Account Settings > Account Settings > Change > More Settings > Advanced > Add. Also, ensure you are using an Exchange account, as this field is not available for other account types.
Recipient Sees Only Your Name as Sender
This usually means Send As permission was granted instead of Send on Behalf. The mailbox owner must check the delegate permissions. They should not grant Editor or Author permission on the Inbox, as this can sometimes grant Send As rights. They should set the Inbox permission to None specifically for Send on Behalf.
Message is Not Saved in the Correct Sent Folder
By default, messages you send on behalf of someone are saved in your own Sent Items folder. To save a copy in the other user’s Sent Items folder, you must CC or BCC yourself on the message. Alternatively, the mailbox owner can create a rule to move messages, but this is not automatic.
Send on Behalf vs Full Access vs Send As
| Item | Send on Behalf | Full Access | Send As |
|---|---|---|---|
| Primary Use | Send transparently for another user | Read and manage another mailbox | Send as if you are the other user |
| Recipient Sees | “On Behalf Of” in header | Not applicable for sending | Only the other user’s name |
| Permission Level | Specific send permission | Read, create, delete items | Full sending impersonation |
| Setup Location | Outlook Delegate Access | Exchange admin center or Outlook | Exchange admin center |
You can now send emails representing a colleague with clear attribution. For broader mailbox management, explore setting up Out of Office replies for another person. An advanced tip is to use the Outlook web app to quickly verify delegate permissions under Settings > View all Outlook settings > Mail > Accounts > Delegation.