When working with the Proton email app in either the web-based client or desktop app it is very unfriendly to easily select multiple, individual messages with e.g. control/space/etc and then easily delete with DEL or SHIFT+DEL like working with Outlook or Gmail with just the keyboard. Additionally, it would be good to open a new compose-email in a separete window and enable dragging/dropping one or more existing email(s) into the new message to forward messages. This would be a great usability improvement.