discourse/app/models/incoming_email.rb

class IncomingEmail < ActiveRecord::Base
  belongs_to :user
  belongs_to :topic
  belongs_to :post

  scope :errored,  -> { where("NOT is_bounce AND LENGTH(COALESCE(error,'')) > 0") }
end

# == Schema Information
#
# Table name: incoming_emails
#
#  id                :integer          not null, primary key
#  user_id           :integer
#  topic_id          :integer
#  post_id           :integer
#  raw               :text
#  error             :text
#  message_id        :text
#  from_address      :text
#  to_addresses      :text
#  cc_addresses      :text
#  subject           :text
#  created_at        :datetime         not null
#  updated_at        :datetime         not null
#  rejection_message :text
#  is_auto_generated :boolean          default(FALSE)
#  is_bounce         :boolean          default(FALSE), not null
#
# Indexes
#
#  index_incoming_emails_on_created_at  (created_at)
#  index_incoming_emails_on_error       (error)
#  index_incoming_emails_on_message_id  (message_id)
#  index_incoming_emails_on_post_id     (post_id)
#