Rated 3 out of 5 stars

But still works then.

Edit:

nope, it's possible to enable it now, but in the compose message window it's obvious that it's not compatible any more:
https://i.imgur.com/9u19tn4.jpg

Please update.

This review is for a previous version of the add-on (1.6.1). 

Rated 3 out of 5 stars

25.5.0 is actual by July 1st 2015.

btw I managed it to make 1.5.7-signed work on latest TB AND on latest Pale Moon - but that workaround doesn't do it anymore with 1.6.0 for Pale Moon - which is, I repeat, not outdated.

But who is still interested:
https://mega.co.nz/#!WNIGBIRK!hT6RVXsT3xQm4_iVyuOKR3X9nG1qLfnpr_wMVsq-HKw

This review is for a previous version of the add-on (1.5.7.1-signed).