Rated 4 out of 5 stars

An extremely useful Add-On. I don't know how I lived without it all those years.

There is a technical issue though - when the Reminder window is open, the list of emails in my main thunderbird window is emptied after a few seconds. Meaning that I open a folder, see the email list for a few seconds, then it's gone. Closing the Mailmindr window fixes this, though.

This review is for a previous version of the add-on (0.7.9.4).