Using ActionMailer Without Rails

ActionMailer is pretty awesome. It does it’s job well, and as a Rails developer, you may be already familiar with it. Then you get tasked to build something that isn’t a Rails application. Using ActionMailer without Rails is easy, with a couple of gotchas.

Setup Your Gemfile

The first step, of course, is to add action mailer to your Gemfile:

gem "actionmailer", "~> 3.2.6", require: "action_mailer"

Perfect. Just run bundle install next and you’re off to the races.

Create The Mailer

Once you’ve got ActionMailer required, you can create a mailer just like before. I setup a directory just like Rails for app/mailers and created mailer.rb inside:

class Mailer < ActionMailer::Base
  default to: "[email protected]"

  def notification(from_email)
    mail(from: from_email, subject: "New notification") do |format|
      format.text
      format.html
    end
  end
end

The format block is what most people would be missing here. We can still render templates just like Rails does, but we have to specify the format(s) we want rendered. You can then create the notification.text.erb and notification.html.erb files in a views directory. I chose app/views/mailers/notification.html.erb for mine.

Wiring It Up

The last step is to configure ActionMailer to look for the proper folder for the views as well as configure your SMTP settings. I setup my project to have an initializers folder like Rails does. This just needs to be run on boot of your application:

ActionMailer::Base.raise_delivery_errors = true
ActionMailer::Base.delivery_method = :smtp
ActionMailer::Base.smtp_settings = {
   :address        => "smtp.gmail.com",
   :port           => 587,
   :domain         => "example.com",
   :authentication => :plain,
   :user_name      => "YOUR_EMAIL",
   :password       => "YOUR_PASSWORD",
   :enable_starttls_auto => true
  }
ActionMailer::Base.view_paths = File.expand_path('../../../app/views/', __FILE__)

You may need to modify the configuration settings here. The view_paths need to point to app/views. ActionMailer will append mailer/notification.html.erb to that path when looking for a template.

That should be all you need to do! The format block was the only part that had tripped me up with this so hopefully you have any easy time with this as well.