We don’t actively try to recruit new developers in any kind of formal way. What we do is use SXEmacs for everything everyday and not hide the fact that we do. :-) That in itself makes people curious and some ask about this thing called SXEmacs. Show them what it is, point them to the web site, encourage them to subscribe to SXEmacs Devel, and even help them get an account on Our Issue Tracker. And low and behold! We have a new developer.
One recruitment tool that we do have is sxemacs.org email addresses. If you’d like one, contact Steve Youngs. Then you can use that email address whenever and whereever you like. Hmm, perhaps not everywhere, it might not look so good if you use it for log in details to a pr0n site. :-P