How Do I Check To See If PEAR Is Installed On My Server or Not?
require_once 'Mail.php';

$from = "me@example.com>";

$to = "you@gmail.com>";
$subject = "Hi!";
$body = "Hi,nnHow are you?";

$host = "mail.example.com";

$username = "me";
$password = "test";

$headers = array ('From' => $from,
  'To' => $to,
  'Subject' => $subject);

$smtp = Mail::factory('smtp',
  array ('host' => $host,
    'auth' => true,
    'username' => $username,
    'password' => $password));
$mail = $smtp->send($to, $headers, $body);

if (PEAR::isError($mail)) {
  echo("<p>" . $mail->getMessage() . "</p>");
 } else {
  echo("<p>Message successfully sent!</p>");
 }

require_once 'System.php';
var_dump(class_exists('System'));

which pear

/usr/bin/pear

sudo apt-get install php-pear

sudo pear install mail

sudo pear install Net_SMTP

sudo pear install Auth_SASL

sudo pear install mail_mime