The problem is: ActionMailer doesn''t include view helpers by default, and helper :all makes it to look for all_helper.rb Similar issue was discussed before: https://rails.lighthouseapp.com/projects/8994/tickets/3945-helper-all-on-by-default https://github.com/rails/rails/issues/928 https://github.com/rails/rails/issues/1582 Steve Klabnik told me to post here: https://github.com/rails/rails/issues/8911 As of rails 3.2.11 the problem is still there: class ContactMailer < ActionMailer::Base helper :all end Produces: LoadError (Missing helper file helpers/all_helper.rb): Shouldn''t it load them all, as in ActionController since ActionMailer doesn''t load helpers by default. PS. Sorry if this is a double post, the first post disappeared somehow. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To view this discussion on the web visit https://groups.google.com/d/msg/rubyonrails-core/-/k9CDusFQavYJ. To post to this group, send email to rubyonrails-core@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en.