Hi @121balu
If you use "Forward an email" action, then it will show the mail trail but to avoid that we could have send a new email and pass the subject & body of the original email.
Pls refer the below sample flow for the workaorund:
1. I have used manual trigger and that accepts subject of an email as input parameter to filter the email that needs to forward:

2. Next, using "Get emails" action we can fetch the required email and apply filter on subject based on the input parameter:

3. Now, send a new email using "Send an email" action and pass the subject & body from the output of "Get emails" action:

If this helps & solves your problem, please remember to give a 👍 and accept my solution as it will help others in the future.
Thanks