We have been using DNS Blacklists for a long time - and the number one DNSBL has been SpamCop.
The last 2-3 days it has been blocking MUCH less than usual - and (obviously) more spam has been delivered to users.
Has anyone else noticed this, have there been changes at SpamCop?
Subject: Spamcop - not working?
I noticed a sharp decline in Spamcop blocks also and determined that the hedge must be down a little due to all of the spoofed addresses, etc. Since then I have added several of the SORBS DNSBLs so that we have another line of defense. Hope this helps.
Subject: RE: Spamcop - not working?
Thanks for the reply.
I added: bl.spamcannibal.org and dnsbl.antispam.or.id - which have been OK, but not as good as SpamCop.
Which DNSBL’s have had the best “hit rate” for you?
Subject: RE: Spamcop - not working?
DNSBL hit rates - start here:
http://chris-linfoot.net/plinks/CWLT-5YAEZY
Is Spamcop not working at all, or are you seeing some hits but fewer than before?
If the latter, some ISPs are now nulling DNSBL queries to popular DNSBLs including Spamcop, apparently to alleviate the load on their name servers.
HTH
Chris Linfoot
Subject: RE: Spamcop - not working?
SPAMCOP is “working” - but we are seeing MUCH fewer blocks. And we did not make any changes to the SMTP servers or configurations when we noticed this.
SPAMCOP used to be, by far, the #1 DNSBL.
Below is current output from 1 server.
SMTP.DNSBL.bl.spamcannibal.org.Hits = 151
SMTP.DNSBL.bl.spamcop.net.Hits = 369
SMTP.DNSBL.dnsbl.antispam.or.id.Hits = 738
SMTP.DNSBL.dnsbl.njabl.org.Hits = 52
SMTP.DNSBL.list.dsbl.org.Hits = 3
SMTP.DNSBL.sbl.spamhaus.org.Hits = 175
SMTP.DNSBL.spam.dnsbl.sorbs.net.Hits = 621
I have tracked the number of DNSBL hits per day and we have dropped from more than 10,000-12,000 to about 1700-2000.
Subject: I have noticed a drop as well, but I have also noticed this week a drop in SPAM in general…
Even w/ spamcop and a couple of other BL sites, I was getting 70-120 SPAM mails per day myself (registered technical contact for 6-7 domains). This week the number dropped to around 25-35 and I have not been able to figure out why.
Subject: RE: Spamcop - not working?
Still looks like a problem with name resolution.
Spam may have dropped but not by a factor of ten - actually it has not dropped at all here and we are still seeing a very healthy number of hits on all the DNSBLs we use.