500 Error when sending single email

I have created a form which sends an email, but when I press submit I get a 500 Error.

After turning on error reporting I get:

Warning: require_once(/usr/local/lib/php/Mail.phpMail.php) [function.require-once]: failed to open stream: No such file or directory in /home/littlecoffeeguy/public_html/webassist/email/PEAR_Mail_using_SMTP_php.php on line 113

Fatal error: require_once() [function.require]: Failed opening required '/usr/local/lib/php/Mail.phpMail.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/littlecoffeeguy/public_html/webassist/email/PEAR_Mail_using_SMTP_php.php on line 113

I am using the PEAR location provided by my host as well as host (localhost) and port 465 with an authenticated account

So I figured that the PEAR location seemed like the issue, and therefore removed 'Mail.php' from the end.

I tried using localhost and port 26 as well as rs1.hostng.co.uk with port 465 but the page just showed that it was busy

Then I got;

Internal Server Error

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

Please contact the server administrator, webmaster@littlecoffeeguy.co.uk 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.

Ive been in touch with the hosting company and Ive been through Level 2 support and am now being told that the Senior Developers need to help who wont be in for another 12 hours :/

See if they can give you a sample PEAR script that works and then we can adapt it. It really sounds like PEAR isn't installed... does it show when your run phpinfo(); on a page?

Im not entirely sure, I searched for PEAR in the phpinfo page and could only find "Phar based on pear" which appears to be enabled

PEAR isn't even installed on that server... that is your issue.