Integrating with Mail Chimp to initiate discount

I want to give free discount of 5% for all registered users. I am using mail chimp for email newletter subscription. So how do I integrate mail chimp with hikashop to send emails to registered users with the dynamically generated coupon code.

I read in the forum that Acymailing integration is easy and the coupon code is generated automatically, but I prefer using mail chimp but with the same functionality - so that coupon code is generated for each users after their registration and the coupon code is send to them via mail

Please let me know how I can acheive this, If you think mailchimp is impossible, then please guide me how I can alter the hikashop and generate automated coupon code on each user registration and send the same via acymailing to users once they complete their registration procedure

Thanks in advance

Thank you Nicolas, will have a look at AcyMailing
Regards
Pete