How to mitigate sending risks and be able to deliver those VERY IMPORTANT emails to your customers’ inboxes no matter what?

Now, Mailtrap has developed the answer to all these questions for Ruby applications: the ActionMailer Balancer: https://mailtrap.io/blog/actionmailer-balancer/

ActionMailer Balancer is an ActionMailer extension that works, well, surprise, as a balancer! It allows proportionally distributing the email sending load between two different sending services and keeping the sending equilibrium in the percentage you need and set up for yourself. For example:

SendGrid 70% / Mailtrap 30% or Postmark 60% / Mailgun 40%.

The Balancer works with any valid ActionMailer delivery method, either built-in, or added from the library, like the one from Mailtrap.