block spam comparison

Block Spam Comparison

Challenge response filters: An "active" sort of spam filter that works by blocking unknown senders' mail from delivery until they prove that they are well-intentioned human beings and not spammers or robots.
Normal popup blockers can stop these.
Spamhaus Project: A british anti-spam organization that provides resources such as the rokso database and a number of popular dnsbl blocklists.
Spam blocker software will filter the emails that you receive and help distinguish it between spam or normal emails.
Many software companies offer limited free trials that allow you to download a free spam blocker for a period on average of between 15 to 30 days.
If you're serious about fighting spam, buy spam blocker software.
A software called mailwasher allows you to set very specific filters so that only true spam gets blocked.
Blacklists are not a terribly effective form of spam filter as they usually do not block or reject e-mail as much as merely route it to some destination of the user's choice (like the trash can).
So, if the mail provider has set up blocklisting or other facilities to reject spam deliveries, then it is spared the necessity of filtering most such mail for its users.
This differs from a block list in that it actively boycotts tcp/ip addresses known to send spam or host spammers.