I am looking for some adaptive email templates
Hey there, pay attention to eSputnik and Stripo.
The first is known as a good and convenient email automation service. There are a lot of great adaptive built-in templates and easy-to-use drag and drop email editor. Moreover, there are interesting one-time offer: you can order the special design of your template for free. It will be developed by eSputnik team. This tool is recognized by G2: https://www.g2.com/products/esputnik/reviews
As for Stripo, it is an independent email template builder. Also nice.