How to use my view helpers in my ActionMailer views?

Question

I want to use the methods I defined in app/helpers/annotations_helper.rb in my ReportMailer views (app/views/report_mailer/usage_report.text.html.erb

Answer 1

For all mailers in Rails 3 (setting "application" helper):

# config/application.rb:
...
config.to_prepare do
  ActionMailer::Base.helper "application"
end