SMTP Email Log

// SMTP Email Log / Kiri Vadivelu / 2026

// Register the Admin Menu

add_action('admin_menu', 'register_all_menus');

function register_all_menus() {

  add_menu_page(

    'Email Log',

    'Email Log',

    'manage_options', // Access for Admin Only

    'smtp-log',

    'render_smtp_log_page',

    'dashicons-email-alt',

    99

);

}   

// Render the Email Log

function render_smtp_log_page() {

    $log_file = WP_CONTENT_DIR . '/email_log.txt';  

    if (!file_exists($log_file)) {

        echo '<div class="notice notice-warning"><p>No log file found yet.</p></div>';

        return;

    }

    // Read lines, reverse for newest-first display

    $lines = file($log_file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

    $lines = array_reverse($lines);

    // Cap at 200 most recent entries

    $lines = array_slice($lines, 0, 200);

    ?>

    <!-- Make the log legible -->

    <div class="wrap" style="text-align:center">

        <h1>SMTP Email Log</h1>  

        <p class="description">Showing latest <?php echo count($lines) ?> event(s). Newest first, maximum 200 entries.</p>

        <style>

            .smtp-log-table { width: 100%; border-collapse: collapse; margin-top: 12px; }

            .smtp-log-table th, .smtp-log-table td {

                padding: 6px 10px; border-bottom: 1px solid #e0e0e0;

                font-family: monospace; font-size: 12px; text-align: left;

            }

            .smtp-log-table th { background: #f6f7f7; }

            .smtp-log-table tr:hover { background: #f0f6fc; }

            .log-error { color: #d63638; font-weight: bold; }

            .log-success { color: #00a32a; }

        </style>

        <table class="smtp-log-table">

            <thead>

                <tr><th>Timestamp</th><th>Message</th></tr>

            </thead>

            <tbody>

            <?php foreach ($lines as $line) :

                // Parse [timestamp] message

                if (preg_match('/^\[([\d\- :]+)\]\s(.*)$/', $line, $m)) {

                    $ts = $m[1];

                    $msg = $m[2];

                } else {

                    $ts = '';

                    $msg = $line;

                }

                $class = '';

                if (preg_match('/^[45]\d{2}/', $msg)) $class = 'log-error';

                elseif (strpos($msg, '250 2.0.0') !== false) $class = 'log-success';

                ?>

                <tr class="<?= $class ?>">

                    <td><?= esc_html($ts) ?></td>

                    <td><?= esc_html($msg) ?></td>

                </tr>

            <?php endforeach; ?>

            </tbody>

        </table>

    </div>

    <?php

}

// Enable Gmail SMTP

add_action('phpmailer_init', 'enable_gmail_smtp');

function enable_gmail_smtp($phpmailer) {

    // Gmail SMTP Settings

    $phpmailer->isSMTP();

    $phpmailer->Host       = 'smtp.gmail.com';

    $phpmailer->SMTPAuth   = true;

    $phpmailer->Port       = 587; // Use 465 for SSL

    $phpmailer->SMTPSecure = 'tls'; // Use 'ssl' for port 465

    $phpmailer->Username   = '[email protected]'; // Your Gmail address

    $phpmailer->Password   = 'abcd efgh ijkl mnop'; // Your 16-digit App Password

    $phpmailer->From       = '[email protected]';

    $phpmailer->FromName   = 'first last';

    // Enable Email Logging

    $phpmailer->SMTPDebug = 2; // Enable verbose debug output (2 = both client and server)

    $phpmailer->Debugoutput = 'enable_email_log';

}

// Complete Events (For testing only)

// function enable_email_log($message, $level) {

//     // Define log file path

//     $log_file = WP_CONTENT_DIR . '/email_log.txt';

//     // Format the log entry

//     $timestamp = current_time('mysql');

//     $log_entry = "[$timestamp] Level: $level - $message" . PHP_EOL;

//     // Append to log file

//     file_put_contents($log_file, $log_entry, FILE_APPEND);

// }   

// Summary Events (Recommended)

// function enable_email_log($message, $level) {

//     $log_file = WP_CONTENT_DIR . '/email_log.txt';

//     // Only log useful lines, skip handshake noise

//     $skip = [

//         'HELO', 'EHLO', '250-', '250 ',  // greeting / capability lists

//         'AUTH', '334',                    // auth exchange

//         'QUIT', '221',                    // session close

//     ];

//     foreach ($skip as $pattern) {

//         if (strpos($message, $pattern) !== false) {

//             return; // skip this line

//         }

//     }

//     $timestamp = current_time('mysql');

//     $log_entry = "[$timestamp] $message" . PHP_EOL;

//     file_put_contents($log_file, $log_entry, FILE_APPEND | LOCK_EX);

// }   

// Brief Events (Minimal)

function enable_email_log($message, $level) {

    // Only log errors and the final 250 delivery confirmation

    if (strpos($message, '250 2.0.0') === false

        && !preg_match('/^[45]\d{2}/', $message)

        && $level !== 4 // level 4 = critical error

    ) {

        return;

    }

    $log_file = WP_CONTENT_DIR . '/email_log.txt';

    $timestamp = current_time('mysql');   

    file_put_contents($log_file, "[$timestamp] $message" . PHP_EOL, FILE_APPEND | LOCK_EX);

}