Thanks for reaching out! I investigated, but I was unable to reproduce this issue, @Gowri_Shankar_RJ! In this case, I believe our support team will be better equipped to help you find the root cause. I recommend you to contact them and confirm the following information in your email:
Steps to reproduce (confirm if you are using the Outlook add in or emailing to Asana directly from your Outlook account).
Screenshot showing the email before it is sent, so we can see the details included in the email
Confirm if the tasks are duplicated of the original task or notifications about actions made on the task you created
URL f this thread so they can see your initial report and screenshot.
I hope this helps! If you have any other questions, please let me know!