Comment 129 for bug 376715

Please add this functionality. Thunderbird 60 drops .xpi support, there are no longer any addons that work with thunderbird 60. The addon "Minimize to tray (revived)" (https://addons.mozilla.org/en-GB/thunderbird/addon/minimizetotray-revived/) is the 12th most popular addon. This very simple functionality needs adding to thunderbird.