AppleInsider rated Unibox "Best Overall" in a recent comparison of Mac email clients. Read the full review here:

http://appleinsider.com/articles/13/12/26/apps-for-your-new-mac-best-email-clients

Another recent article: http://macreview.com/2013/12/unibox-review

Stay tuned, we are already working on the next update to make Unibox even better.