Select email provider at runtime in a Ruby on Rails application

Recently we had a requirement where emails were to be delivered to a specific group of users by choosing the provider at run time. In short, we are required to deliver the emails by dynamically selecting a provider and not just through a pre-configured provider.Rails provide these Dynamic Delivery Options to override the SMTP settings per mail. But, if you have an existing application with various mailers, applying delivery_method_options will require updating individual mailer action. In this blog, we'll go through the approaches that will work without modifying any existing mailer actions.