ging/mailboxer — pull request #99 by bennick (2012-12-11 22:29:30+00:00)
Title: Added support for STI

All I really did was query the base class when finding a receipt. This is necessary because Rails required that we store the base model for the STI models in the type column of the polymorphic associations.

http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#label-Polymorphic+Associations