Enabling Sent Items Copy features within Exchange Online for Shared Mailboxes

Shared mailboxes are great. We use them for a variety of scenarios within our environment. One of the most common user complaints we receive about shared mailboxes is desktop Outlook placing items sent from or on behalf of the shared mailbox in the individual users’ sent items folder. This leads to confusion and loss of efficiency.

There is an option that finally (…FINALLY…) addresses this issue without having to run elaborate registry scripts on each user machine. As of July 2017, this option isn’t available within the EXO Admin Center. You would figure they would incorporate it into the GUI there first, but they didn’t. It is only available within the Office365 Admin Center.

We are going to look at the GUI option available, examine the mailbox attributes associated, then setup a PowerShell script to change one shared mailbox as well as all shared mailboxes within the environment. Login to the Office365 Admin Center, expand Groups, then click on Shared mailboxes.

Select a shared mailbox. I chose GIS for my example. The information panel pops up on the right-hand side. Here are the options available to us without having to go into the EXO Admin Center. Click on Edit within the Sent items row.

This is what we want to enable! There are two toggles here, for sent as the mailbox, and sent on behalf of the mailbox. Enabling these options and clicking Save will now show the Sent items row as “Copied to mailbox” instead of “Not copied to mailbox” on the information panel.

A view of the information panel after enabling the Sent Items Copy settings.

Let’s connect to Azure PowerShell and load up EXO. Doing a FL return on the shared mailbox we just modified:

Get-Mailbox -Identity sharedmailbox@domain.com | FL 

Brings up these two attributes. These are the attributes that we triggered from the GUI toggle within the Office365 Admin Center earlier.

MessageCopyForSentAsEnabled           : True

MessageCopyForSendOnBehalfEnabled     : True

To set these attributes for a single mailbox is as follows:

Set-Mailbox -Identity sharedmailbox@domain.com -MessageCopyForSendOnBehalfEnabled $true -MessageCopyForSentAsEnabled $true

If you are like me, you want to enable these settings on all your shared mailboxes in your environment. First, we have to return all shared mailboxes that the Sent Items Copy isn’t yet set:

Get-Mailbox -RecipientTypeDetails shared | Where-Object{$_.messagecopyforsentasenabled -eq ""} 

FYI, if you ever have the need to return all shared mailboxes that has the Sent Items Copy enabled:

Get-Mailbox -RecipientTypeDetails shared | Where-Object{$_.messagecopyforsentasenabled -eq "true"} 

Now we will take the selection of the shared mailboxes that don’t have the Sent Items Copy enabled yet and combine that with the Set-Mailbox command that enables both Sent Items Copy attributes.

Get-Mailbox -RecipientTypeDetails shared | Where-Object{$_.messagecopyforsentasenabled -eq ""} | Set-Mailbox -MessageCopyForSendOnBehalfEnabled $true -MessageCopyForSentAsEnabled $true 

There... We just enabled this great feature for all the shared mailboxes within our environment. Hopefully this might help someone who is facing an issue that requires a similar solution.

Disclaimer: Sample environment is hybrid (Exchange 2013/EXO), screenshots from July 2017. As with the nature of the cloud, future updates may make this article outdated, unappreciated, obsolete, and/or just plain pointless.