Rails Mailer’s Subject Inference

Turns out you can leave out the :subject key when sending mail in Rails 3, so long as you have the proper keys / translation in your en.yml (or other language files):

 Notifications < ActionMailer::Base; def new_user( user ); mail :to => user.email; end 

Will map to:

 en: notifications: new_referral: subject: "Welcome to the app!"