Hi @Sameer Kuppanath ,
Welcome to our forum,
Regarding your requirement to automatically replace the mail in the mailbox, it actually exceeds the basic functions of Outlook, which means that we couldn't meet it directly in Outlook.
As a reference, you could try to search and create any VBA script or develop any add-ins to meet it, I have researched a lot about it but only found a related script about deleting duplicate messages in a folder, please kindly check if it could also be helpful to you.(Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)
If that's invalid or you still need more assistance about script, please kindly understand here we mainly focus on general issue on Outlook desktop client. It's suggested to post your issue in any development forums. Also, if you couldn't wirte/modify an script for yourself, you could try to hire any development experts to help you.
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