📧 Tutorial Sending Emails in Laravel with CID Images

📌 Table of Contents

Introduction
Preparation
Creating Email Helper
Creating Email View with CID Image
Using Helper to Send Email
Conclusion

🔧 Preparation

Ensure Laravel is installed.

Configure SMTP in .env:

MAIL_MAILER=smtp
MAIL_HOST=smtp.example.com
MAIL_PORT=587
MAIL_USERNAME=your_email@example.com
MAIL_PASSWORD=your_password
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=your_email@example.com
MAIL_FROM_NAME="Your Name"

Run php artisan storage:link to access images from storage.

📌 Creating Email Helper

Create app/Helpers/EmailHelper.php:

<?php

namespace App\Helpers;

use Illuminate\Support\Facades\Mail;
use Exception;

class EmailHelper
{
    public static function sendEmail($to, $subject, $message, $attachments = [], $cc = [], $bcc = [])
    {
        try {
            Mail::send([], [], function ($messageObj) use ($to, $subject, $message, $attachments, $cc, $bcc) {
                $messageWithInlineImages = self::processInlineImages($message, $messageObj);
                
                $messageObj->to($to)
                           ->subject($subject)
                           ->html($messageWithInlineImages);
                
                if (!empty($cc)) $messageObj->cc($cc);
                if (!empty($bcc)) $messageObj->bcc($bcc);
                if (!empty($attachments)) {
                    foreach ($attachments as $attachment) {
                        $messageObj->attach($attachment);
                    }
                }
            });

            return true;
        } catch (Exception $e) {
            logger("EmailHelper: " . $e->getMessage());
            throw new Exception("Failed to send email: " . $e->getMessage());
        }
    }

    private static function processInlineImages($body, $messageObj)
    {
        return preg_replace_callback('/<img[^>]+src=["\'](.*?)["\']/i', function ($matches) use ($messageObj) {
            $imagePath = $matches[1];
            
            if (strpos($imagePath, '/storage') === 0) {
                $filePath = storage_path('app/public' . parse_url($imagePath, PHP_URL_PATH));
                
                if (file_exists($filePath)) {
                    $cid = 'cid_' . uniqid();
                    $messageObj->embed($filePath, ['content-id' => $cid]);
                    return 'src="cid:' . $cid . '"';
                }
            }
            
            return $matches[0];
        }, $body);
    }
}

🖼 Creating Email View with CID Image

Create resources/views/emails/sample.blade.php:

<!DOCTYPE html>
<html>
<head>
    <title>Email with CID Image</title>
</head>
<body>
    <h2>Hello, this is an email with a CID image</h2>
    <p>Here's an inline image:</p>
    <img src="/storage/email/logo.png" alt="Logo">
</body>
</html>

Ensure the image is stored at storage/app/public/email/logo.png

🔍 Understanding `processInlineImages`

The processInlineImages function is responsible for converting images from local paths (/storage/...) to Content-ID (CID) to be included as inline attachments in emails.

How It Works:

Detect <img> tags in the email using preg_replace_callback.
Extract src from <img> tags to check if the image is from Laravel storage (/storage/...).
Convert image path to absolute server path using storage_path().
Embed the image in the email with $messageObj->embed() to encode as a CID Image.
Replace image src in HTML with cid:unique_id, so the image displays from the email, not from an external URL.

HTML Email Transformation Example:

Before:

<img src="/storage/email/logo.png" alt="Logo">

After:

<img src="cid:cid_123456789" alt="Logo">

With this method, images remain displayed even when the email recipient is offline.

📤 Using Helper to Send Email

In a controller or service, use the following code to send an email:

use App\Helpers\EmailHelper;

EmailHelper::sendEmail(
    'recipient@example.com',
    'Email Subject',
    view('emails.sample')->render()
);

✅ Conclusion

With this method, images in emails remain displayed even when the recipient is offline. This is useful for sending emails with branding or important images without relying on external sources.

Happy coding! 🎉