Mark as read buttons havent worked for months and months. It is literally what I used to use this add-on for. Marking useless mails as read so I wouldn't have to open them one by one. Also opening a specific mail SOMETIMES works but mostly it is unresponsive. This used to be so good. Other add-ons work better but dont show the preview and only take me to the inbox as a shortcut after showing me that I have unread emails. I have reinstalled this several times hoping it would work but the devs clearly do not care any more.