Feature Request in MS Outlook

I manage my official mails in MS Outlook. I have setup "Rules" to move the messages from my Inbox to designated folders. Apart from these rule based categorization of mails, I have certain manual categorization as well (done at the end of completion of tasks in those mails).

Request for feature:
When a new mail arrives with the earlier categorized mail subject, there should be an indication in the Inbox that earlier mails with this subject has been categorized in a particular folder. This way I could get

• I could get related mails easily
• I can perform manual categorization easily