How do I get SpamAssassin to stop using a blacklist to block or reject email?
SpamAssassin is rarely set up to actually reject email, so people asking this question usually have a problem with their mail server configuration, not SpamAssassin. Remove the option to reject email with a blacklist from your server configuration.
An example rejection message from postfix looks like this, in /var/log/mail.log:
Feb 2 10:44:44 panic postfix/smtpd: NOQUEUE: reject: RCPT from lab75-4-82-245-152-54.fbx.proxad.net[220.127.116.11]: 554 5.7.1 Service unavailable; Client host [18.104.22.168] blocked using zen.spamhaus.org; http://www.spamhaus.org/query/bl?ip=22.214.171.124; from=<email@example.com> to=<firstname.lastname@example.org> proto=ESMTP helo=<proxad.net>
That is caused by the following line in /etc/postfix/main.cf:
There is nothing wrong with rejecting email in this manner, but it is something that people do often ask how to do.