Exchange Shared mailboxes have sent items send a copy to the sent items folder

Exchange Shared mailboxes have sent items send a copy to the sent items folder

Reference: https://blogs.technet.microsoft.com/exchange/2015/03/03/want-more-control-over-sent-items-when-using-shared-mailboxes/

Microsoft took it out and then put it back in. 

It can be enabled by setting feature enable flag to TRUE:

For emails Sent As the shared mailbox: set-mailbox <mailbox name> -MessageCopyForSentAsEnabled $True

For emails Sent On Behalf of the shared mailbox: set-mailbox <mailbox name> -MessageCopyForSendOnBehalfEnabled $True

If you then want to disable the feature again, you can do it as follows:

For emails Sent As the shared mailbox: set-mailbox <mailbox name> -MessageCopyForSentAsEnabled $False

For emails Sent On Behalf of the shared mailbox: set-mailbox <mailbox name> -MessageCopyForSendOnBehalfEnabled $False