Rated 2 out of 5 stars

Από τον/την Χρήστης Firefox 6e292b στις Οκτ. 24, 2013 ·

In Thunderbird this extension does not go in the sense that totalization of folders is not correct and sometimes numbers disappear.
You must control because this extension is wrong with the last Thundebird release 24.
Bye.

από τον Χρήστης Firefox beeb85 (δημιουργός) στις Οκτ. 24, 2013 ·

Hi, the add-on does not control the numbers themselves, it only displays the numbers that Thunderbird provides.

You need to file a bug on Thunderbird itself about the numbers being incorrect, explaining which numbers, and roughly when they disappear.