Sendmail DNSBL blocking authenticating users
I have a problem with sendmail. I am using the zen.spamhaus.org dnsbl, and it is doing a wonderful job of blocking incoming spam from open relays. But it is blocking my users who are on a dynamic ip range from any isp remotely. They should be able to authenticate and send messages no matter where they are as long as they authenticate right? I just want to use the blacklist to block incoming mail to my server that is being distributed to our email addresses.
I want to block people that are hosting mail servers and sending mail to my domain from isp sub-nets. But I don't want to block my users that are sitting on isp subnets using their mail client to authenticate over smtp and send an email from my mail servers. Does anyone have any experience with this problem?