>We were also using the senderscore RBL based on Reindel and others >recommendations, but disabled it after it just rejected too much ham.
The senderscore.org RBL scores for low reputation are a pain sometimes but those senders need to know how to filter outbound email properly and detect compromised accounts. Senders won't change or improve if there isn't some pain or motivation. This shows a fundamental problem in mail filtering that needs to be addressed somehow. When a good mail filter blocks email from a mail server listed on an RBL, who is at fault. The sender blames the receiving mail filter because the bounce messages aren't understand- able to the average user. So the sender has no easy way to contact the recipient unless they use a different email address. Then the recipient contacts their own support group (us) and we look like the bad guy for blocking the email when it is really a repuation problem with the sender that is very hard to get in contact with. Then if you can get in touch with the sending mail server admin, they usually don't know enough about how RBLs or mail filtering works well enough so you have to spend a lot of time showing them http://senderscore.org or http://multirbl.valli.org/ and explain what all of that stuff means. In the end, we have to whitelist the IP from Postscreen because we can't get the sender to fix their own problem and we open ourselves for possible spam getting through. Their's no good answer to this solution but to push back to make mail server admins aware of the spam coming from their server and the low reputation of their mail server IP. Most people I have worked with to explain this have been very receptive and thankful for the help since they tell me they have experience "odd or strangeness" with some emails to certain recipients. Dave
