Review for xultray for gecko 1.9.2 by coder
Rated 4 out of 5 stars
It absolutely needs to show if there are unread messages. Either via a different icon, icon marker, or a number showing how many unread messages there are (like Thunderbird does natively on OS X). That is an essential feature, otherwise there is no point putting it in the tray.
To create your own collections, you must have a Mozilla Add-ons account.