Rated 3 out of 5 stars

Works fairly well on Gmail and Ymail; install & config were quick and easy. However, caused various problems with my Yahoo log-in and several Yahoo apps. Webmail may somehow log you out of Yahoo and/or cause it to lose your prefs. I normally stay logged in to Yahoo all the time, and now I find myself dumped out frequently. Even when logged in, the Yahoo homepage no longer shows how much new mail I have- Webmail supercedes that function. It's not a bad add-on, just causes some conflicts and the annoyance factor led me to uninstall.

This review is for a previous version of the add-on (1.5.3).