@DocControl
The link in the DocuSign email to the recipient is a unique, private link, which is only intended for the recipient and it clearly states that link should not be forwarded. If this email is forwarded or shared and someone else clicks on it, how would DocuSign know it is someone else? Right, there is no way to do so.
You can add additional security by configuring authentication on various levels to enforce a login to the DocuSign Account so envelopes cannot be opened without authentication, for example on domain level when you set up SSO and enforce login to access envelopes.
There is also the option to add a second factor for authentication, e.g. an Access Code or SMS to verify the recipients identity before accessing the envelope.