Setting Up Email in a Rails 4 app with Action Mailer in development and SendGrid in production using Heroku

Here is a demo of how I created an email w/ user-mailer in rails

First off, from the Rails Guide generate a UserMailer

Screen Shot 2013-12-21 at 7.34.47 PM

Then in the user_mailer.rb create a function that sends the email

Pretty simple right?  Now we need to create the view.  This is where you can design the email and whatever text you want to put in it. Create a file in the app/views/user_mailer folder.  The name of the file should match the name of the function you defined in the user_mailer.rb file.  Mine is welcome_email.html.erb

Screen Shot 2013-12-21 at 7.45.23 PM

Now that we have the function to send the email, and the text of the email itself,  we just need to add a line in the controller to have it send the email when we want it to.

You can call the mailer function wherever you want to send the email, in this case we can just send it when a new user signs up

Screen Shot 2013-12-21 at 8.50.09 PM

Now we need to set up the config files for the email address we will use to send emails. For development, in the config/environment/development.rb file:

Screen Shot 2014-02-23 at 8.00.13 PM

Set the config.action_mailer.default_url_options to ‘localhost:3000’ in development, or whatever port you are using to test.  In production, you would set it to the url of your production app.  Then set up the email smtp settings according to your email provider.  I’ve shown the settings for gmail here.

So great, now we have it set up so a new user will receive an email, at least in development.  Now getting this working in production can be slightly harder.  But I’m going to walk through one super easy solution of how to set this up using Heroku and SendGrid, but there are probably a million different ways to do this depending on your hosting, your email, etc.

So the first thing to do before moving to production is to protect the sensitive email sign in information that we just put in the config/environment/development.rb.  The easiest way to do this is to use environment variables, and a simple way to do that is to use the figaro gem.  I wrote a quick post on how to setup environment variables with the figaro gem here, so take a minute and set that up in your app first.  This will keep your email login info from getting pushed to github, in case you are using a public repository.  It should then look something like this:

So, assuming you have your app pushed to heroku for production, the next thing we need to do is setup an email add-on for your heroku app.  Of course you could fully create your own email solution, but if you know how to do that then you wouldn’t be reading this blog, would you? So, for a simpler solution, first you can choose one of the email related add-ons from the heroku add-ons page.  I happen to use SendGrid as I think its one of the simplest to set up and use, so that’s what I’ll go through here.

Add SendGrid to your heroku app by running

heroku addons:add sendgrid:starter

Now SendGrid will have automatically generated a username and password that you can see by running

heroku config:get SENDGRID_USERNAME
heroku config:get SENDGRID_PASSWORD

or simply running heroku config will show you all the heroku config variables.

Next, go to config/environment/production.rb and add our email settings there:

So you can see that SendGrid has set up environment variables on heroku for us, giving us the SENDGRID_USERNAME and SENDGRID_PASSWORD.  This is the same idea that we just did in development using the figaro gem.

Ok, so now push to heroku, migrate the database, and see if the mailer is working in production.  Not too difficult right?  Stay tuned for a follow up post where I’ll describe how to send email asynchronously with sidekiq and redis.

14 Responses to Setting Up Email in a Rails 4 app with Action Mailer in development and SendGrid in production using Heroku

  1. Pingback: What I learned today | Setting Up Email in a Rails 4 app with Action Mailer in development and SendGrid in production using Heroku

  2. DUDE YOU ARE SUCH A LIFE SAVER!!!!! I have spent days + trying to figure this out and your blog was all I needed to help fix my issues!

    Thanks for your documentation of your endeavours!

  3. edswartz says:

    This was very helpful for me! The rest of the site looks interesting and will explore. I’m in a similar boat of teaching myself Rails (after taking a course) and glad to see others running into similar issues.

  4. jamie says:

    Thanks for the great walkthrough. It helped me set up email notifications for this small project:
    I hope you don’t mind if I submit your article as an additional resource here: Thanks again.

  5. Josh Frankel says:

    Excellent article. Really well written and clear. I was wondering about keeping the credentials safe from prying eyes at the beginning of the post.

  6. Germano says:


  7. Pingback:

  8. isss says:

    I have a question, If I’m only going to use the production environment, it shouldnt affect what settings I have in the development environment config file, correct?

  9. BlueBird says:

    It finally worked! Thank you so much! Yay!

  10. Mary says:

    Thank you!

  11. Dude, thanks for that one! I was trying to use Gmail through ActionMailer, but would get an SMTP error as Gmail would block the access to Heroku as an unknown device. I’m glad people created things like SendGrid and that you took your time to share your experience! 🙂

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