Working with Action Mailer Callbacks in Rails

If you want to perform some operation after the mail delivery you can use the Action Mailer callbacks.

Action Mailer allows for you to specify a before_action, after_action and around_action. 

• Filters can be specified with a block or a symbol to a method in the mailer class similar to controllers.
• You could use a before_action to populate the mail object with defaults, delivery_method_options or insert default headers and attachments.
• You could use an after_action to do similar setup as a before_action but using instance variables set in your mailer action.
  

 you can use callbacks same as like in the controllers.here is an example of it.

class UserMailer < ActionMailer::Base

  after_action :set_delivery_options

  def feedback_message(user)

    @user = user

    mail

  end

 

  private

 

    def set_delivery_options

      # You have access to the mail instance,

      # @user instance variables here

      # your code here

    end

end