Contact form issue: static to wordpress

Hi,
I am almost done going from static to wordpress on an older site. The last thing I need to do is get the contact working (yea I don’t feel like downloading a plugin and trying to get it to work with my preexisting css). When I click the send button, I get this error message:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@mamlesip.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

I linked to the contactengine.php file directly on my contact page using the exact address of the file location on my site.

Any suggestions?

Thanks,
Sean