Warning: mail(): Failed to connect to mailserver at “localhost” port 25, verify your “SMTP” and “smtp_port” setting in php.ini or use ini_set() in C:\xampp\htdocs\ashley\assets\mail\estimate.php on line 39
ERROR!
Furthermore, to use Gmail to send email, you need to go beyond just setting it up correctly in your code. Please read this post I made some months ago. Google regularly updates its policy, so you might want to check that it is still working on a regular basis.