On this page

Ruby on Rails

This example shows how to send an email for user signups. You can also checkout this gem for more advanced features.

Setup ActionMailer

Let's generate a Mailer class. Mailer classes function as our controllers for email views.

rails generate mailer UserNotifierMailer

Now we open up the mailer we've just generated, app/mailers/user_notifier_mailer.rb and add a mailer action that sends users a signup email.

1class UserNotifierMailer < ApplicationMailer
2  default :from => 'any_from_address@example.com'
3
4  # send a signup email to the user, pass in the user object that   contains the user's email address
5  def send_signup_email(user)
6    @user = user
7    mail( :to => @user.email,
8    :subject => 'Thanks for signing up for our amazing app' )
9  end
10end

Now we need a view that corresponds to our action and outputs HTML for our email. Create a file app/views/user_notifier_mailer/send_signup_email.html.erb as follows:

1<!DOCTYPE html>
2<html>
3  <head>
4    <meta content='text/html; charset=UTF-8' http-equiv='Content-Type' />
5  </head>
6  <body>
7    <h1>Thanks for signing up, <%= @user.name %>!</h1>
8    <p>Thanks for joining and have a great day! Now sign in and do
9awesome things!</p>
10  </body>
11</html>

If you don't have a user model quite yet, generate one quickly.

1rails generate scaffold user name email login
2rake db:migrate

Now in the controller for the user model app/controllers/users_controller.rb, add a call to UserNotifierMailer.send_signup_email when a user is saved.

1class UsersController < ApplicationController
2  def create
3    # Create the user from params
4    @user = User.new(user_params)
5    if @user.save
6      # Deliver the signup email
7      UserNotifierMailer.send_signup_email(@user).deliver
8      redirect_to(@user, :notice => 'User created')
9    else
10      render :action => 'new'
11    end
12  end
13
14  private
15
16  def user_params
17    params.require(:user).permit(:name, :email, :login)
18  end
19end

Alright, now we're cooking! Let's get it all going through SendGrid.

Configure ActionMailer to Use SendGrid

In config/environment.rb specify your ActionMailer settings to point to SendGrid's servers.

1ActionMailer:\:Base.smtp_settings = {
2  :user_name => 'apikey', # This is the string literal 'apikey', NOT the ID of your API key
3  :password => '<SENDGRID_API_KEY>', # This is the secret sendgrid API key which was issued during API key creation
4  :domain => 'yourdomain.com',
5  :address => 'smtp.sendgrid.net',
6  :port => 587,
7  :authentication => :plain,
8  :enable_starttls_auto => true
9}

That's it! When a new user object is saved, an email will be sent to the user via SendGrid.

(error)

Danger

As a best practice, you should not store your credentials directly in the source but should instead store them in configuration files or environment variables. See this tutorial on environment variables in Rails. And for Rails Versions 5.2+ see Securely storing custom credentials in Rails.