How to send emails with multiple, dynamic smtp using Actionmailer/Ruby on Rails

Question

I saw this post but mine is slightly different:

Rails ActionMailer with multiple SMTP servers

I am allowing the users to send mail using their own SMTP crede

Answer 1

Here is a solution that I came up with based on the previous answers and comments. This uses an ActionMailer interceptor class.

class UserMailer < ActionMailer::Base
  default from: proc{ @user.mail_settings[:from_address] }      

  class DynamicSettingsInterceptor
     def self.delivering_email(message)
       message.delivery_method.settings.merge!(@user.mail_settings)
     end
   end
   register_interceptor DynamicSettingsInterceptor
end