In order to filter spam on server side KEIN MAIL is using DNS based blacklists (DNSBL). These lists are usually automatically generated and consist of the IP addresses where spam reportedly originated during the last few hours. KEIN MAIL servers do not exchange messages with these servers. At KEIN MAIL we are currently using the following blacklists:

http://bl.spamcop.net
http://ix.dnsbl.manitu.net