Rated 3 out of 5 stars

If one is experiencing the greyed out Send button with 1.4.4 (I am), one can download the old 1.4.3 version and then disable automatic updates. 1.4.3 is available from:
https://addons.mozilla.org/en-US/thunderbird/addon/correct-identity/versions/

This review is for a previous version of the add-on (1.4.4).