Rated 4 out of 5 stars

Thank you for your good extension;
But when I upgraded Thunderbird to version 51Beta, I couldn't send messages.
Please fix this bug.
Thanks again

This review is for a previous version of the add-on (1.8.2). 

Hi,
Thanks for your feedback.

For bug reports, please use the email support. It'll be easier for us to communicate.
As an example, the compatibility with TB51 is fixed in internal dev version and I could ask you to test it.
Cheers,
Michel