Rated 4 out of 5 stars

Nice and smart tool! Thank you very much for providing this.

I have only one thing that I don't like about it. When I am writing e-mails and I select text, I can't use the backspace and that is a bit annoying - sometimes.
Another thing is that I don't see a highlight, when I use the highlight function. Thunderbird 9.0.1
One more issue is the display of translation text.
I am currently translating into German and a result is showing like this: WörterbuchAdjektivendlos, unendlich, unzählig, uferlos
The first word are actually 3 words. The tranlation actually starts after the Words WörterbuchAdjektiv (what means Dictionary Adjective) and for some reasons the spaces or swallowed. That makes it a bit hard to read.
If I try to copy the translation into the clipboard by selecting the text and trying to use the right mouse click context menu, the translation window just closes before I can copy it. The shortcut CTRL+C works.
Just as some feedback.
I like the extension anyway.
Anything else is fantastic!

This review is for a previous version of the add-on (0.6.1-signed.1-signed).  This user has a previous review of this add-on.

I'll investigate issues reported by you and will try to fix them. Can you please provide more details about translation issue (like source language, destination language, exact phrase, expected result)? I'll appreciate if you will use support site.
Update: issue with context menu in the translation window fixed; highlight issue fixed. I cannot reproduce translation issues so far.