I used to love Postbox until the latest 6th version. Sure, they've - allegedly - made it run faster but they've also removed extension support, blocked any way

I used to love Postbox until the latest 6th version. Sure, they've - allegedly - made it run faster but they've also removed extension support, blocked any ways to hack in a calendar (which could previously be done by adding a permanent browser tab pointing to Google Calendar) and seriously hurt legibility with its new design by removing dividing lines, decreasing contrast across the board and giving all the icons a bright random colour. A real shame as there are no real alternatives.