how to integrate external autoresponder with membership?

I wish to integrate an external autoresponder (AR) with our membership plugin, so that I can register the new members at any level using the registration form from this AR.

The AR that I wish to integrate is run using WP Plugin called myMail (powered by Mandrill smtp).

According to @Alexander Rohmann this is possible, but I do not have any idea as to how this is done, leave alone a detailed process.

These days, all membership scripts prominently feature EASY integration with variety of standard and custom autoresponders, primarily because email marketing is indispensible for success.

Please guide me step-by-step on this please OR incorporate this feature with a detailed guide in the plugins documentation.

I hope to hear from you asap.