Rated 3 out of 5 stars

It's decent for basic reading/writing emails, but...
1) there's nothing to distinguish a mail message from a meeting request. After I get an email, I have to check my Android phone's *stock* mail app to see if the message was actually a meeting request. Big pain, as I often forget to do this.

2) minor: doesn't refresh the 'message read' status properly, so I have to click back and forth on a directory to force it to clear the 'unread' status on the dir.

On the plus side, since my original review, the "Save All" Attachments button/right-click functions properly now -- thanks!

On the downside, since http://www.zdnet.com/mozilla-scraps-thunderbird-development-email-client-not-a-priority-anymore-7000000469/ , I'm really not sure I want to pay for add-ons.

This review is for a previous version of the add-on (23.1). 

1) The UI for meeting requests is part of Lightning. If you have Lightning installed, you should see details of meeting requests. If not, this is a bug and please file a support request.
2) This is a known issue, but technically the flag you are talking about is the "New" flag and not the "Unread" flag.
Thanks for the fair and reasonable review.

Rated 4 out of 5 stars

Very good -- does most of what I need! When trying to set up a particular Exchange account as IMAP I had problems since the company apparently wasn't running an SMTP server, but this allows me to send mail!

One minor problem I have is that the "Save All" Attachments button/right-click does nothing, so I have to download multiple attachments individually. :-(

This review is for a previous version of the add-on (19.3).