#15 way to prevent spam

[Hanspeter Niederstrasser]

I've been getting (as well as the nms-cgi support form apparently), lots of spam being sent to me via my formmail install. What I've noticed from all the spams I've gotten is that all the fields on the form are set to something by the bot. Having a hidden form field set to nothing and then checking for a value when submitted should point out all spams since users won't be able to see that field. Would this be something useful to incorporate into the next version of formail and/or TFmail?