exchange 2016中通過共享郵箱發送的郵件，不會保存到共享郵箱的已發送郵件文件夾中，而是會保存到用戶自己的已發送郵件文件夾。

解決的方法

通過設置共享郵箱的兩個屬性，將已發送郵件保存一份副本到共享郵箱的已發送郵件文件夾中，如圖。

官方參考鏈接

Want more control over Sent Items when using shared mailboxes? – You Had Me At EHLO… https://blogs.technet.microsoft.com/exchange/2015/03/03/want-more-control-over-sent-items-when-using-shared-mailboxes/

Messages sent from a shared mailbox aren't saved to the Sent Items folder of the shared mailbox in Outlook https://support.microsoft.com/en-us/help/2843677/messages-sent-from-a-shared-mailbox-aren-t-saved-to-the-sent-items-fol

Exchange 2016共享郵箱不保存已發送郵件的問題