Use a different delivery_method with ActionMailer just for a single email?

Question

Given a Mailer instance in Rails 3, is there a way to override the delivery_method on it?

I want to push certain emails out through a high-priority transport, and others use a busier, low-priority method.

I can adjust the config at runtime and change it back again, but this is fraught with potential side-effects.

Answer 1

It turns out that doing this affects just this specific Mailer, without changing ActionMailer::Base globally.

class SomeMailer < ActionMailer::Base
  self.delivery_method = :high_priority  

  def some_email(params)
  end
end

You can also do this (warning: will affect all instances of AnotherMailer), if you have the instance up-front:

mail = AnotherMailer.whatever_email
mail.delivery_handler.delivery_method = :something_else

These don't seem to be documented, but work.