I find myself being Joe Jobbed yet again. I suppose this happens to everyone once in a while, but that doesn't make it any easier to accept. The worst thing about joe jobs is that you get so many bounces with in a short period that genuine bouncers are easily missed.
The last time I had this problem, I looked at SPF to see if it can do any good. Unfortunately not, Too few mail servers bother with SPF checks to validated the authenticity of the sender address/IP so SPF sadly is nothing more than a burden on the DNS server.