Correct me if I am wrong here, I assume you are trying to view a contact form of someone's elses website in hope to get a contact mail or something, as others pointed out, these days its rare to see that kinda of thing on the source code.
Most site will have that on a config file or other means where using the internal mail server they will dispatch a mail to the contact of that website with your information or save it on a database where they can view or even with an external smtp and there is no way to intervent on that process as it is done internally, unless like metioned above you have some way to access the server or even hack it.
Have you thinked about using alternative ways to reach those people ?
For example let's say you want to contact people from websiteA then you could for example try to whois their domain for contact information.
Since I can't post links, I can't direct you to any whois search but, you can find it on sites like godaddy, enom, networksolutions.
Another idea is you could try to search the domain or company in case at google maps or at bbb you might find something.
. The main thing is to help OP