The reason it comes from VCGMail@ is to ensure that the email is sent in accordance to Anti-SPAM regulations. VCG does not have access to these emails once they're sent per our privacy policy.
If someone submits a form request through your website via the "Send File" or "Quotes" page, you will receive an email from VCGMail@VCGCorporate.com stating "Interested site visitor..." with their contact information and what they have submitted. If you receive an email like this, that means your client has in fact sent it through your form pages on your website.