At RMTWRK we are building the world’s to help match companies hiring remote or distributed teams with people who are looking for a more flexible work environment. As a result our rails app has two user types, Company Users, people doing the hiring and Individual Users, people wanting to be hired and we wanted to have separate confirmation emails for each user type. Additionally we wanted to use ’s API for sending emails rather than through SMTP (more on this later), and lastly we wanted to use the amazing gem to inline the CSS styles in our emails before sending. largest remote only jobs board Mailgun Premailer is one of the long standing and best written ruby/rails libraries around and one of the easiest to customize, workaround, and override. It does so much though that it can sometimes be hard to know where to start. Devise We are going to go over the 3 methods (or degrees, if you will) of customizing Devise’s emails. Simple customization of Devise’s default emails Customizing the “layout” and “templates” used by Devise for sending emails Overriding how Devise sends emails to use an API (Mailgun) instead of SMTP Method 1: Method 2: Method 3: I’ll briefly touch on and link to other resources for the first 2 methods Method 1: Simple customization of Devise’s default emails If you only want to modify a few simple things about the layout of something like the email or email then this is the method for you. First run the following in your terminal and then you can edit the views for the emails you are interested in inside of email confirmation password reset views/devise/mailer rails generate devise:views For further details, the best place to look would be the on GitHub. Devise Readme Customizing the “layout” and “templates” used by Devise for sending emails Method 2: If you want to go a bit further and customize the layout that each email template is rendered into then you can do so by creating your own Mailer class that subclasses . Devise also has a great Readme on how to do this here: . **Devise::Mailer** How To: Create custom layouts There are a couple of potential gotchas to be aware of with this method. If you have two resource types, like say and (the names of our actual models), the simplest way to have two separate mailers is to use the method in each .rb model file (simplified example below). If you plan to move the location of the mailer templates, be sure to delete the existing templates in “devise/mailer” as they will override your other views. User Individual **devise_mailer** resource This is an example of a simple customized Devise Mailer: class RmtwrkDeviseMailer < Devise::Mailerhelper :application include Devise::Controllers::UrlHelpers _# eg. `confirmation_url`_ default template_path: 'rmtwrk/devise/mailer default from: 'RMTWRK 'default reply_to: 'RMTWRK 'layout 'mailer_rmtwrk'end # helpers defined within `application_helper` rmtwrk@wrkhq.com rmtwrk@wrkhq.com And you can tell your model to use this mailer using the method like this: Individual devise_mailer class Individual < ApplicationRecorddevise :database_autenticatable,..., :confirmable def devise_mailerRmtwrkDeviseMailerendend But what if you wanted to do some other things to the email before sending it? That’s where method 3 comes in. Overriding how Devise sends emails to use an API instead of SMTP Method 3: Our constraints: Sending email vis an API rather than SMTP. Most email providers recommend using their API rather than SMTP for a variety of reasons. Here are and reasons as examples. Sendrid’s Mailgun’s Two models; and , using Devise. resource User Individual Separate branding, i.e. files per model. layout Inlining our CSS using Premailer. In order to accomplish this the essential piece of the puzzle is overriding the method(s) you are interested in. For this example we will only focus on the email confirmation email. This is handled by the method by default, which uses and SMTP by default. Devise::Mailer confirmation_instructions ActionMailer Here is what our final custom Devise Mailer will look like: I hope that this has been helpful! Please leave comments or questions and I’d be happy to respond, but let’s be honest the most likely person to stumble on this in 10 months or so looking for an example of how to do this is probably me, hi future me! Best — Andrew Gertig
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