needs better UI Rated 2 out of 5 stars

I generally like the idea, however I think it needs some heavy UI polishing.
The to, cc and bcc fields are to large. I would be nice if they had the same size as the subject field (I know it's hard to do that because of the way the emails are styled, which I like, but they're definitely too big). They look great on large screens as they are now, but most of the users don't have large screens. Also the form field should have the same styling as the other fields. Since cc and bcc are not used all the time, it would be great if they were hidden at the beginning, and enabled with two buttons 'add cc' and 'add bcc' like in gmail.
The three buttons (save, send, discard) look really odd alone on one line... maybe you could move them on top? I also don't like the buttons in the attachment pane, and I really like the way the attachment pane looks by default in thunderbird.
What disturbs me the most is the use of the MCE. There are too many buttons on too many lines. Why on Earth would I need to embed flash or forms in an email? The MCE should be only on one line only. You could include what commands are available in the extension options (I personally like the Source button, but I don't think that there are many who would use it).