eSignature email address verification question

I have been challenged on the authenticity of a signature that I personally obtained from a client via Docusign.  The challenge is that there is no evidence of what email address the request was sent to and that I could have sent it to my own email and signed the document myself had I wanted to.

Can I prove what email address the signature request was sent to from the document itself, or is my only option a screen shot from the Docusign folder? I would have thought that info would have been embedded in the signed document, but I can’t find it.

Thank you