Logs your sent email for PHP.

log_your_mail.php

#!/usr/bin/php
<?php
/*
 * Don't forget to set following in your php.ini:
 *      sendmail_path = /path/to/mail_log.php
 *
 * You can test with following php code:
 *      mail('user@email.dev', 'subject', 'body');
 */
$mail = '';
$pointer = fopen('php://stdin', 'r');
while ($line = fgets($pointer)) {
    $mail .= $line;
}

$title = 'Email at '.date('Y-m-d H:i:s');

$content = "----------------------------\n"
          .$title."\n"
          ."----------------------------\n"
          .$mail."\n\n";

$cmd = '/usr/bin/notify-send';
$cmd .= ' ' . escapeshellarg($title);
$cmd .= ' ' . escapeshellarg($mail);
shell_exec($cmd);
file_put_contents('/run/shm/mail.log', $content, FILE_APPEND);