Contact Problems

Fix Exchange Send on Behalf Permission Creating the Wrong Delegate

Camila Milosovich Oct 12, 2026 868 views

Question details

The user is attempting to assign 'Send on Behalf' permissions to a delegate, but Exchange creates the permission for a different, unintended user or an unexpected GUID-like object.

How to Fix Exchange Send on Behalf Permission Assigning the Wrong Delegate

Product: Microsoft Exchange
Device & OS: not provided
Scenario: An administrator is configuring mail flow and delegate permissions for a distribution list or user mailbox using the Exchange Admin Center.
Observed behavior: Exchange assigns the Send on Behalf permission to a random GUID-like directory object instead of the selected delegate, leaving the intended user without permission.

Before you start

Ensure you have Exchange Administrator credentials and verify that the intended user object is fully synchronized and healthy in your Active Directory environment.

Solution 1Recommended

Use Exchange Management Shell (PowerShell) to Assign Permissions

Bypassing the Exchange Admin Center UI and using PowerShell forces Exchange to assign permissions to the exact identity object you specify, preventing GUID confusion.

The web-based Exchange Admin Center can sometimes struggle with name resolution if there are hidden duplicate objects. Using Exchange Management Shell allows you to specifically target the exact User Principal Name (UPN) or alias of the delegate.

Open Exchange Management Shell

Launch the Exchange Management Shell as an administrator on your server or connect via remote PowerShell.

Review Current Delegates

Run the command Get-DistributionGroup -Identity 'YourGroupName' | Format-List GrantSendOnBehalfTo to see the current list of delegates and identify the incorrect GUID object.

Assign the Correct Delegate

Run the Set-DistributionGroup command using the syntax: Set-DistributionGroup -Identity 'YourGroupName' -GrantSendOnBehalfTo @{Add='CorrectUserUPN'}. If modifying a mailbox, use Set-Mailbox instead.

Use Exchange Management Shell (PowerShell) to Assign Permissions

Identity Verification: By using the exact email address or UPN of the delegate in PowerShell, Exchange bypasses ambiguous name resolution and targets the precise mailbox.

Solution 2

Identify and Remove Stale Directory Objects

Since this issue is often triggered by duplicate or stale active directory accounts, cleaning them up resolves the underlying identity conflict.

Free Microsoft Office alternative

Switch to WPS Office for a Lightweight and Compatible Experience

While resolving Microsoft Exchange server conflicts requires administrative PowerShell troubleshooting, managing your daily documents shouldn't be complicated. WPS Office provides a free, highly compatible, and user-friendly alternative to Microsoft Office for all your word processing, spreadsheet, and presentation needs.

1. Visit the WPS Website: Go to the official WPS Office website to access the latest version.
2. Download the Installer: Click the free download button to save the installation package to your computer.
3. Install and Launch: Run the downloaded file and follow the on-screen prompts to start creating and editing documents immediately.

Fully compatible with Microsoft Word, Excel, and PowerPoint formats (.docx, .xlsx, .pptx).Lightweight architecture that runs smoothly on older hardware without draining system resources.Familiar tabbed user interface, ensuring a seamless migration with zero learning curve.Built-in PDF editing tools seamlessly combined into one powerful office suite.

microsoft office alternative - wps office

Frequently Asked Questions

Can an Exchange user have both 'Send As' and 'Send on Behalf' permissions?

Yes, Microsoft documentation indicates that a user can hold both permissions simultaneously without inherent conflict. However, best practice suggests assigning only the specific permission needed to avoid administrative confusion.

Why does the Exchange Admin Center assign a GUID instead of a username?

This typically occurs when there is an ambiguous name resolution failure in the background. If Active Directory contains a duplicate, stale, or orphaned object matching the search string, Exchange might bind the permission to the wrong object's GUID.

Does this permission bug affect all users in my Exchange environment?

Usually, no. This issue typically isolates itself to certain users who have conflicting directory data or duplicate alias entries. You will often find that granting the exact same permission to a different user works flawlessly.

Outlook & Email Problems