Installing the Mailer

Hey friends! Welcome to "Symfony Mailer with Mailtrap"! I'm Kevin, and I'll be your postmaster for this course, which is all about sending beautiful emails with Symfony's Mailer component, including adding HTML, CSS - and configuring for production. On that note, there are many services you can use on production to actually send your emails. This course will focus on one called Mailtrap: (1) because it's great and (2) because it offers a fantastic way to preview your emails. But don't worry, the concepts we'll cover are universal and can be applied to any email service. And bonus! We'll also cover how to track email events like bounces, opens, and link clicks by leveraging some relatively new Symfony components: Webhook and RemoteEvent.

Transactional vs Bulk Emails

Before we start spamming, ahem, delivering important info via email, we need to clarify something: Symfony Mailer is for what's called transactional emails only. These are user-specific emails that occur when something specific happens in your app. Things like: a welcome email after a user signs up, an order confirmation email when they place an order, or even emails like a "your post was upvoted" are all examples of transactional emails. Symfony Mailer is not for bulk or marketing emails. Because of this, we don't need to worry about any kind of unsubscribe functionality. There are specific services for sending bulk emails or newsletters, Mailtrap can even do this via their site.

Our Project

As always, to deliver the most bang for your screencast buck, you should totally code along with me! Download the course code on this page. When you unzip the file, you'll find a start/ directory with the code we'll start with. Follow the README.md file to get the app running. I've already done this and ran symfony serve -d to start the web server.

Welcome to "Universal Travel": a travel agency where users can book trips to different galactic locations. Here are the currently available trips. Users can already book these, but there are no confirmation emails sent when they do. We're going to fix that! If I'm spending thousands of credits on a trip to Naboo, I want to know that my reservation was successful!

Installing the Mailer Component

Step 1: let's install the Symfony Mailer! Open your terminal and run:

composer require mailer

The Symfony Flex recipe for mailer is asking us to install some Docker configuration. This is for a local SMTP server to help with previewing emails. We're going to use Mailtrap for this so say "no". Installed! Run:

git status

to see what we got. Looks like the recipe added some environment variables in .env and added the mailer configuration in config/packages/mailer.yaml.

MAILER_DSN

In your IDE, open .env. The Mailer recipe added this MAILER_DSN environment variable. This is a special URL-looking string that configures your mailer transport: how your emails are actually sent, like via SMTP, Mailtrap, etc. The recipe defaults to null://null and is perfect for local development and testing. This transport does nothing when an email is sent! It pretends to deliver the email, but really sends it out an airlock. We'll preview our emails in a different way.

Ok! We're ready to send our first email! Let's do that next!