I just pushed a new version of Maily ( https://github.com/markets/maily ) v0.6.0, adding Rails 5.1 compatibility and some other improvements: lazy attributes to fetch data, emails description, better handling of internal exceptions, fixed assets pipeline integration and some internals cleanup.

I also released InvisibleCaptcha ( https://github.com/markets/invisible_captcha ) v0.9.3, with Rails 5.1 fixes as well.

Thanks a lot to all contributors!