lib/action_mailer/log_subscriber.rb
# frozen_string_literal: true require "active_support/log_subscriber" module ActionMailer # = Action Mailer \LogSubscriber # # Implements the ActiveSupport::LogSubscriber for logging notifications when # email is delivered or received. class LogSubscriber < ActiveSupport::LogSubscriber # An email was delivered. def deliver(event) info do if exception = event.payload[:exception_object] "Failed delivery of mail #{event.payload[:message_id]} error_class=#{exception.class} error_message=#{exception.message.inspect}" elsif event.payload[:perform_deliveries] "Delivered mail #{event.payload[:message_id]} (#{event.duration.round(1)}ms)" else "Skipped delivery of mail #{event.payload[:message_id]} as `perform_deliveries` is false" end end debug { event.payload[:mail] } end subscribe_log_level :deliver, :debug # An email was generated. def process(event) debug do mailer = event.payload[:mailer] action = event.payload[:action] "#{mailer}##{action}: processed outbound mail in #{event.duration.round(1)}ms" end end subscribe_log_level :process, :debug # Use the logger configured for ActionMailer::Base. def logger ActionMailer::Base.logger end end end ActionMailer::LogSubscriber.attach_to :action_mailer