```ruby
class PantographMailer < ActionMailer::Base
  default from: Settings.admin.email

  def tweet_failed(message)
    @message = message

    mail(
      to: Settings.monitoring.email,
      subject: message,
      host: Settings.host
    )
  end
end
```

Fix mailer settings using new format
user
```ruby
class PantographMailer < ActionMailer::Base
  default from: Constant.admin.email

  def tweet_failed(message)
    @message = message

    mail(
      to: Setting['advanced.monitoring_email'],
      subject: message,
      host: Constant.host
    )
  end
end
```
assistant