I used to love Postbox until the latest 6th version. It may be a bit faster but extension support was completely removed and there are also no ways to add (or

I used to love Postbox until the latest 6th version. It may be a bit faster but extension support was completely removed and there are also no ways to add (or hack in) a calendar (which could previously be done by adding a permanent browser tab pointing to Google Calendar). They also seem to have done something to the 5th version that prevents me from adding my calendar back, which I found out after downgrading from 6. On top of that, the new design has terrible legibility as most dividing lines that gave structure were removed, contrast was reduced across the board and every single icon seems to have been given an exceptionally bright and completely random colour. I would be so happy if anyone knows of a way to add a calendar back into Postbox 5 (be it tab with Google Calendar or Lightning). I've since moved to Mailbird but that client doesn't even allow for emails to be moved between accounts. There are no alternatives to Postbox 5 that come even close imo.