Sent items as shared mailbox but the sent item to only be saved in the other mailbox sent items

New Contributor



365 Exchange Online

Outlook 2016 


Is it possible to give full access to a mailbox with 'send as' or 'send on behalf' permissions but the sent item is to only be saved in the sent items of the other mailbox sent items? Not a copy saved.


I can only find Powershell commands for a copy to be saved in both sent items.


Set-Mailbox <delegator mailbox name> -MessageCopyForSendOnBehalfEnabled $true






8 Replies
best response confirmed by Philip Cassidy (New Contributor)

From the Exchange side, you're using the right command, but you're correct that it will save a copy in both sent items folders.

I'd strongly recommend that method as it's easiest to manage, but the other option is to configure local workstations using group policy, so long as you are using Outlook 2010 or higher. That should make it so that it's only saved in the one folder:

  1. Click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following registry subkey:
    Note The x.0 placeholder represents your version of Office (16.0 = Office 2016, 15.0 = Office 2013, 14.0 = Office 2010).
  3. On the Edit menu, point to New, and then click DWORD Value.
  4. Type DelegateSentItemsStyle, and then press Enter.
  5. Right-click DelegateSentItemsStyle, and then click Modify.
  6. In the Value data box, type 1, and then click OK.
  7. Exit Registry Editor.


Thank you! Tested on a user and it worked :)  

get-mailbox -recipienttypedetails sharedmailbox | set-mailbox -MessageCopyForSentAsEnabled $True  -MessageCopyForSendOnBehalfEnabled $True


Run this commaned it will enable for all shared mailbox.

Has a Powershell cmdlet showed up for the shared account DELETED email?  I'm doing this with a registry entry today. 

Hello all,

our freeware "UniSent Flow" moves a message sent from a shared mailbox to user's Deleted items folder.


You might have posted this in 2018, but I've found it in 2021 and it's helped me massively. I can't believe Microsoft doesn't have this set as the default.
Thank you! it works well with me.

but you need to run the command whenever you create a new mailbox or migrate a mailbox.