On modern Rails versions, prefer using the official API via ActionMailer::Base.register_interceptor.
Our gem Mail Magnet Show archive.org snapshot allows you to override e-mail recipients in ActionMailer so all mails go to a given address.
This is useful for staging environments where you want to test production-like mail delivery without sending e-mails to real users.
Posted by Henning Koch to makandra dev (2010-09-08 18:37)