Shared mailbox copies items "sent as" to both personal and the shared mailboxes sent items.

Question

Hello!

I have a scenario in Microsoft 365 where users have delegated access to send as a shared mailbox. Two users have a "problem" where the sent items show up both in their personal mailboxes sent folder and the shared mailbox sent folder. Is this a feature or can I somehow prevent it? The vast majority of users do not get the sent items into their personal mailboxes, only in the shared mailbox because MessageCopyForSentAsEnabled is active.

I´ve tried most things I could think of, remove DelegateSentItemsStyle, new profile, Microsoft SaRa and a new computer to name a few but the issue persists.

Something that might be good to know is that there was and still is to some extent a large migration from on-premises to M365 ongoing, which is why some users had the DelegateSentItemsStyle DWORD in the first place.

Is there a way to prevent sent items that was sent as a shared mailbox from showing up in user mailboxes? Or am I way off here and that´s simply how it´s supposed to work?

Thanks in advance!

BR,

Jonathan

Answer 1

Dear Jonathan,

Good day! Thank you for posting to Microsoft Community.

I understand that you have an issue regarding Shared mailbox copies items "sent as" to both personal and the shared mailboxes sent items.

Please note that by default, messages sent from the shared mailbox aren't saved to the Sent Items folder of the shared mailbox. Instead, they are saved to the Sent Items folder of the person who sent the message. When you send or reply to a new message from the shared mailbox, Outlook automatically sends or replies from the sender's account. From your description, if the MessageCopyForSentAsEnabled is active, the sent items should show up both in the personal mailbox sent folder and the shared mailbox sent folder.

Please see Configure shared mailbox settings - Microsoft 365 admin | Microsoft Learn and Messages sent from a shared mailbox aren't saved to the Sent Items folder - Exchange | Microsoft Learn for more info.

In case you have any further queries, please let me know.

Thank you for your precious time and have a nice day.

Best Regards,

Ashraf | Microsoft Community Moderator