Blacklisting is a method of controlling how badly we get hammered by spammers. On the average day, we have about 40,000 attempted emails right now. On average, we block 90% of all them for various reasons or 36,000. By using RBLs(Relay Block Lists), we eliminate approximately 15,000 of those up front and that means we don't have to scan them further and allows us to move the rest of the email a bit faster.
Blacklisting block email senders based on the ip address(or the Internet address of the sending email server), not on the From email address or on the content of the message. In fact, we don't see the actual email address. We drop the connection after gathering the From and To email address of the envelope.
The sender will get a message back that their email message was not accepted and has a link to http://www.lcrcomputer.com/rbl.html . If they go to that web page, there instructions on what they can do to contact LCR Computer(forward the rejection message to firstname.lastname@example.org ).
Quite often instead of trying to contact us, the sender will contact you by an alternate means. In those cases, you must send us an email to us asking us to look into the problem. We need their email address. Because we block so many messages, there is almost no way for us to figure out which email is from Aunt Susie or from someone at your paper supplier without knowing their email address.
Also, we need to investigate within 3 weeks of the blocking of an email. The logs in our spam filter are running 3-4 weeks in time right now. Looking for an email from 6 weeks ago will not work.
Once we get a request, we look at several technical aspects and respond according to what we find. 99% of the time, we remove the block. If we find technical problems, we will advise the sender what those issues are. This is technical information and we don't expect the sender to understand them, but they need to forward this information to those in their company responsible for their email services.
In those rare times, we don't automatically release an ip address block, we may request more information from the sender. We do not accept email from email senders that don't follow basic Internet rules for sending email. In general, we refer to the rules detailed at http://postmaster.aol.com as we basically follow the same practices and requirements of AOL.
We also do not accept email from mail servers on dynamic ip addresses or any server that shows signs of having been recently compromised(broken into) by spammers.
One other note, the From address we gather in our logs is called the envelope address. It is NOT necessarily the same From address inside the email that you see when you open an email. Compare this to a letter you get via USMail. The return address on the envelope does not necessarily have any relationship to the return address on the letter inside. The envelope From could be from a mass mailer company while the From inside will show the email address of the company that wants you to buy their product.