I can use SCRYPTmail in Tor Browser 5.5.3 from linux without problems. I think the features "Tor Browser support" and "Email Filter Rules" can be removed from poll.
There is limited space for emails, so we have to regularly clear our boxes. If I could see in which folder I still have emails (even readed), for example - trash bin, it will be more comfortable. Maybe some flags next to folders list?
Aliases removed from poll