Suppose that an Outlook user has access to their personal mailbox and to the additional (shared) mailboxes (usually 'Info' <info@company.com>, 'Sales' <sales@company.com>; etc.) on an Exchange server. When a user sends an email from a shared mailbox, the email is saved in the 'Sent Items' folder of the user's mailbox, not the shared mailbox's 'Sent Items' folder.
This add-in ensures that the message sent from the second mailbox address will stay in the mailbox that it originated from (i.e., the sent message goes to the 'Sent Items' folder of the mailbox the item was sent from).
Also, the add-in allows a user the ability to see who was the original author of the message placed in the shared mailbox's 'Sent Items' folder.