In January 2007, MAPS (Mail Abuse Prevention System) co-founder Paul Vixie noted on the NANOG mailing list that he continues to receive significant traffic from sites attempting to query the “rbl.maps.vix.com” blocking list.
It appears that RBLSMTPD, a tool to allow sites to utilize DNSBLs to block mail, widely utilized in conjunction with qmail, will default to querying rbl.maps.vix.com. If you use RBLSMTPD, please review your configuration to ensure that you’re not contributing to this problem.
If you are attempting to use the MAPS RBL, please do not simply change over to the blackholes.mail-abuse.org zone. The MAPS services are not free, and are blocked from unregistered access. Please see the MAPS website for more information.
If you’re looking for a free, reputable blocking list suite to try, my recommendation would be to consider Spamhaus’s ZEN combined list. I plan to post an article about them very soon, and I’ll link to that from here, after it’s posted.
It's very unlikely that you would see a bounced email message making reference to rbl.maps.vix.com. If you do see such a bounce, it is likely in error. Contact the site (from another email account or via telephone call) and point them toward this site for further information.