Rated 5 out of 5 stars

Version 1.29a works fine but taking Mozilla an absolute age to release it. Very annoying to get update requests time after time and day after day to 'upgrade' from version 1.29a to version 1.29 which does not work.

This review is for a previous version of the add-on (1.2.9). 

Turning automatic update off would help.
Open Add-ons Manager (menu > Tools > Add-ons), open Confirm-Address's detail page and press "Off" radio button of Automatic Updates.

[Nov. 14, 2018]
It is with great appreciation, I announce that Confirm-Address 1.3.0 which supports Thunderbird 60.* is now available. I thank all the Confirm-Address users for your patience.

Rated 3 out of 5 stars

Worked great with TB Portable version 45. Will not work with version 52. No error messages but nothing happens when click 'send' mail. Pity, needs update.

This review is for a previous version of the add-on (1.2.9). 

I apologize that there is an issue on sending procedure at Confirm-Address 1.2.9 on Thunderbird 52. The issue has been fixed and already sent to Mozilla Foundation a few days ago, it is currently waiting for Mozilla's review. Would like you to wait until the review is done, or download Confirm-Address 1.2.9a from our support site.