Has there been any more discussion/progress on adding a hashcash (www.hashcash.org) stamper to Thunderbird? I did find this change request from April 04; http://bugzilla.mozilla.org/show_bug.cgi?id=229686 But can't find anything since then. I have worked out how to add the X-Hashcash header to Thunderbird mails, but this involves me calculating the stamp in a separate client and copy/pasting into the header field, not very automated! :) Time to resurrect the change request?.... John.