I've been having some issues the last couple of weeks in receiving e-mail, and having finally noticed some errors in mail.log referencing some RBL spam sites, I looked in to it a bit more.
The two RBLs in Richard's /etc/postfix/main.cf are:
the first, dsbl.org, was giving errors every e-mail, thus deferring them (though not bouncing them, I think). spamhaus.org was often giving errors, but not always. I checked dsbl.org, and it says they've shut the system down:
DSBL is GONE and highly unlikely to return. Please remove it from your mail server configuration.
DSBL was a blocklist specialized in listing open relays and open proxies. To put it simply, DSBL listed IP addresses of computers that could be tricked into sending spam by anybody. This was a very successful strategy. Nowadays open relays and open proxies are rare, spammers hardly ever use them any more and no software seems to come with an open-by-default policy any more.
I didn't find much on spamhaus.org (nor did I look too deeply) about the situation. In any case, I've removed both of these from my main.cf file and things are working again.
I'd like to hear if anyone knows why I should try to replace these....I guess I'll see if there is a significant increase in spam.
You are correct, I had not updated these settings yet. My mistake.
I had not noticed it because of the success I have with the greylisting. Spam has decreased dramatically when i started this. Even without the RBL stuff. DSBL is gone but spamhaus is still there but using different servers.
I've changed my settings and the documentation to use zen.spamhaus.org.
14 Jan 2009
I've been having some issues the last couple of weeks in receiving e-mail, and having finally noticed some errors in mail.log referencing some RBL spam sites, I looked in to it a bit more.
The two RBLs in Richard's /etc/postfix/main.cf are:
the first, dsbl.org, was giving errors every e-mail, thus deferring them (though not bouncing them, I think). spamhaus.org was often giving errors, but not always. I checked dsbl.org, and it says they've shut the system down:
I didn't find much on spamhaus.org (nor did I look too deeply) about the situation. In any case, I've removed both of these from my main.cf file and things are working again.
I'd like to hear if anyone knows why I should try to replace these....I guess I'll see if there is a significant increase in spam.
18 Jan 2009
You are correct, I had not updated these settings yet. My mistake.
I had not noticed it because of the success I have with the greylisting. Spam has decreased dramatically when i started this. Even without the RBL stuff. DSBL is gone but spamhaus is still there but using different servers.
I've changed my settings and the documentation to use zen.spamhaus.org.
To read more about the different spamhaus server read: http://www.spamhaus.org/faq/answers.lasso?section=DNSBL%20Usage#202