<p>In my PHP web app, I want to be notified via email whenever certain errors occur. I'd like to use my Gmail account for sending these. How could this be done?</p>

You could use PEAR's mail function with Gmail's SMTP Server
Note that when sending e-mail using Gmail's SMTP server, it will look like it came from your Gmail address, despite what you value is for $from.
(following code taken from
About.com Programming Tips
)
```
```
<?php
require_once "Mail.php";

$from = "Sandra Sender <sender@example.com>";
$to = "Ramona Recipient <recipient@example.com>";
$subject = "Hi!";
$body = "Hi,\n\nHow are you?";

// stick your GMAIL SMTP info here! ------------------------------
$host = "mail.example.com";
$username = "smtp_username";
$password = "smtp_password";
// --------------------------------------------------------------

$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>");
 }
?>
```
```