The rblsmtpd Spam Protection Program

Spam Blacklists and rblsmtpd

The amount of spam is increasing; as methods to block and filter spam become more sophisticated, the methods being used to deliver it are also evolving. The RBL (Realtime Blackhole List) is the first level of defense in this ongoing battle to minimize and manage the impact of spam on both the people and the resources of your organization. We at AlterHosting understand the importance of spam problem, and take every possible step to protect you and your organization from unsolicited commercial and bulk email. The rblsmtpd program is the first level of spam protection, this most comprehensive tool is included in all hosting packages, and FREE for all AlterHosting clients.
The rblsmtpd blocks mail from RBL-listed sites (servers). The RBL was created by Mail Abuse Prevention System (MAPS) LLC. RBL, short for Realtime Blackhole List, is a list of IP addresses whose owners refuse to stop the proliferation of spam. The RBL usually lists server IP addresses from ISPs whose customers are responsible for the spam and from ISPs whose servers are hijacked for spam relay.

RBL sources

• bl.spamcop.net
• dev.null.dk
• list.dsbl.org, using rbldns as of 2002-03
• multihop.dsbl.org, using rbldns as of 2002-03
• or.orbl.org, down as of 2001-10
• orbs.dorkslayers.com
• orbz.gst-group.co.uk
• relays.ordb.org
• relays.osirusoft.com
• unconfirmed.dsbl.org, using rbldns as of 2002-03
• etc

Normally rblsmtpd uses a 451 error code in its limited SMTP conversation. This tells legitimate clients to try again later. It gives innocent relay operators a chance to see the problem, prohibit relaying, get off the RBL, and get the mail delivered.

Together with SpamAssassin, rblsmtpd program helps to keep greater part of spam off your mail boxes.