Hmm..
I've already requested rDNS for my nameservers, and they're working allright (
http://www.dnsstuff.com/tools/ptr.ch?&ip=87.117.246.196 and
http://www.dnsstuff.com/tools/ptr.ch...7.117.246.197). Despite that I still recieve the "Reverse DNS entries for MX records" error when I check the domains using my nameservers through dnsreport!?