Emails "sent as" a user are not stored in user's "Sent Items" folder

[JohnM1075]

We have a notification mailbox that we use to send emails "as" various users in our office, so the notifications box has "Send As" permissions to the various users' mailboxes. When an email is "sent as" a user, we want the email to be stored in that user's "Sent Items" folder; instead, the email is only stored in the notification mailbox's "Sent Items" folder. 

Is it possible to achieve the desired result?

Thanks.

[#2]

Hi @JohnM1075 ,

I'm assuming you are notifications mailbox is shared mailbox. That is the only way you can keep emails in sent mailbox. You can do it by going to Microsoft 365 admin portal > Teams & Groups > Shared mailbox > Select mailbox and under Sent items click on Edit.

[#3]

Hi @JohnM1075,

the MS solution  (see @Adin_Calkic' suggestion) assumes you'll get 2 copies of one sent email in both Sent Items folders. 

If you wish to have only one sent mail, google for UniSent add-in for Outlook.