Rated 3 out of 5 stars
I'm giving a good 3 star review, because I don't know that this extension is the problem for sure. I have the following problems:
- Tons of drafts saved with the original "conversation" in Gmail (although not in Thunderbird)
- Missing email, only some of which I have been able to find using the web interface for Gmail.
- Although copy-sent-to-current, a copy is made in the sent items folder anyway (pretty sure this is gmail in action). When I use something other than Thunderbird with this extension, a reply copy is not made to the folder/label of the message being responded to. That means I don't know which messages in the sent items folder I have copied to the corresponding folder/labels and which I have not.
I really had high hopes for this extension. And now, I believe TB3 added the option "place replies in the folder of the message being replied to", making this extension relatively superfluous.