Rated 1 out of 5 stars
Mnenhy used to be an absolutely essential extension for me, because it made using POPFile for SPAM filtering fairly convenient. Unfortunately, the author has not been able to keep up with Thunderbird's development, and every couple iterations of the software break Mnenhy. In current versions of Thunderbird, it causes the email preview pane to misbehave badly, and prevents message windows from displaying at all.
This was a great extension, but it appears to be dead. Even if it's brought back to life, Thunderbird's rapid development cycle, combined with the author's occasional update cycle, makes it unusable in the long term.