Rated 5 out of 5 stars

Don't know why my earlier review got deleted. Like the post title says, works perfectly. Don't forget to follow the configuration instructions. Recommend setting HashCash token to 22 bits: full point reduction in spamassassin for only a few seconds of minting time.

This review is for a previous version of the add-on (1.5.3). 

Hope this post from me, the maintainer of the code will keep your review up.