If you do not know anything about DNS records and how they work then this will not make a great deal of sense to you. My niece was having trouble sending email to someone she knows as it would bounce back saying mail.theuncle.com was on a blacklist. I checked and it seemed the reason was because the reverse lookup of the mail server IP address was not available at all. I pulled up good old Interland, my hosting company for ‘theuncle.com’, and created a ticket. I ended up getting an email saying it was fixed and closed. I checked the records by doing a lookup and noticed it had the old IP address of a mail server of theirs that no longer exists. I tried to get to my mail server to no avail. This meant that no email would be able to go out or come in. I had to re-open that ticket, then call them up and specify that the tech. that ‘fixed’ the reverse broke all of my email resolving. The guy fixed the record back to the proper IP address and so email works again but the original problem seems to still exist. So I still have a ticket open for it and my temper is a rising.