Hmm ... try to echo on the screen
Instead of :
mail( 'linden.940@gmail.com', 'Feedback Form Results"', $send_email);
try
echo "$send_email";
Do you see all the information?
Something wrong with your php syntax, can you re-check it again?
mail( 'linden.940@gmail.com', 'Feedback Form Results"', $send_email);