[rspec-users] rails3/rspec2: how to write mailer tests?

[nathanvda]

This will sound awfully stupid, but i have no idea how to start
writing any mailer tests.

I have a mailer class

    class SmsMailer < ActionMailer::Base

      def fake_sms(envelope)
        mail(:to => envelope.user.email)
      end
    end

how do I test this?
I tried googling for documentation, but was unable to find something
relevant (probable used wrong search terms).

Or do i just do view-tests on the corresponding view?