Sample configuration of mails_viewer to allow the mails real sent to "pragmatic.ly" domain

mails_viewer_config.rb

config.action_mailer.delivery_method = :file
config.action_mailer.file_settings = {
  location: 'tmp/mails',
  smtp_settings: {
    address:              "localhost",
    port:                 25,
    domain:               'localhost.localdomain',
    user_name:            nil,
    password:             nil,
    authentication:       nil,
    enable_starttls_auto: true
  },
  send_if: lambda { |mail| mail.destinations.select { |address| address =~ /@pragmatic.ly$/ }.any? }
}