​@vishnu 

If you want the envelope to appear to come from a different user, you have to impersonate that user—meaning you obtain an OAuth access token as that user.

DocuSign’s current best practice for impersonation is to use JWT Grant (JSON Web Token) authentication.

Your integration has a public/private key pair.

Your application constructs a JWT that indicates “I want to impersonate user X,” signs the JWT using your private key, and sends it to DocuSign.

DocuSign returns an OAuth token for the specified user (assuming proper permission and consent have been granted).

You then use that token in your Authorization: Bearer <token> header to call the Envelope Send (or Create/Update) endpoint.

When you send the envelope using that token, the envelope is sent by that user, and recipients will see that user’s name/email as the sender in DocuSign’s email.

References on JWT Impersonation

• DocuSign: How to Use JSON Web Tokens (JWT) Auth

• DocuSign JWT Auth Quickstart Guide