We added b.barracudacentral.org as an RBL on our Plesk Servers. But we are seeing slow connecting times to the SMTP Port. If we remove the b.barracudacentral.org, then the SMTP replies very quick. We use two other RBLs and they work fine. Also we are using the b.barracudacentral.org on our Exim servers and they are very happy. BTW, we use FreeBSD. Are we doing something wrong?
smtp stream tcp nowait/1000 root /usr/local/psa/qmail/bin/tcp-env tcp-env -Rt0 /
usr/local/psa/qmail/bin/rblsmtpd -r b.barracudacentral.org -r bl.spamcop.net -r sbl-xbl.spamhaus.org /usr/local/psa/qmail/bin/relaylock /usr/local/psa/qmail/bin/qmail-smtpd /usr/local/psa/qmail/bin/smtp_auth /usr/local/psa/qmail/bin/true /usr/local/psa/qmail/bin/cmd