Send emails using Rails with SMTP
Learn how to integrate Rails with Resend SMTP.
Prerequisites
Section titled “Prerequisites”Before you start, you'll need:
- A Resend API key
- A verified domain
Setup your environment
Add these lines of code into your environment config file.
config/environments/environment.rb config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { :address => 'smtp.resend.com', :port => 465, :user_name => 'resend', :password => ENV['RESEND_API_KEY'], :tls => true }Send email using Rails Action Mailer
Then create a
UserMailerclass definition.app/mailers/user_mailer.rb class UserMailer < ApplicationMailer default from: 'Acme <onboarding@resend.dev>' # this domain must be verified with Resend def welcome_email @user = params[:user] @url = 'http://example.com/login' mail(to: ["delivered@resend.dev"], subject: 'hello world') end endAnd create your ERB email template.
app/views/user_mailer/welcome_email.html.erb <!doctype html> <html> <head> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type" /> </head> <body> <h1>Welcome to example.com, <%= @user.name %></h1> <p>You have successfully signed up to example.com,</p> <p>To log in to the site, just follow this link: <%= @url %>.</p> <p>Thanks for joining and have a great day!</p> </body> </html>Initialize your
UserMailerclass. This returns anActionMailer::MessageDeliveryinstance.Ruby u = User.new name: "derich" mailer = UserMailer.with(user: u).welcome_email # => #<ActionMailer::MessageDelivery:153700, @mail_message=#<Mail::Message...>, @processed_mailer=...>Finally, you can now send emails using the
deliver_now!method:Ruby mailer.deliver_now! # => {:id=>"a193c81e-9ac5-4708-a569-5caf14220539", :from=>....}
Examples
Section titled “Examples”Rails SMTP Example
See the full source code.