Playsafe, Jeroen usually spammed with the from as Casino Bonus.
View the source of the emails and look for the last ip address you see in the header…this will give the originating source.
This stuff can be confusing and I had to do a bit of research on tracking originating ip addresses for spam…
Get the ip and do a search here:
http://openrbl.org/
It will tell you anything from spam complaints listed to the originating server and the abuse address to report to.