How to catch error exception in ActionMailer

Question

The problem is how can I catch exception in delivering mail by ActionMailer. For me it sounds impossible, because in this case ActionMailer should sent mail to mailserver, a

Answer 1

class ApplicationMailer < ActionMailer::Base
  rescue_from [ExceptionThatShouldBeRescued] do |exception|
    #handle it here
  end
end

Works with rails 5 onwards. And it's the best practice.