We use a mail filter product that determines if an e-mail is (a) spam or (b) contains something malicious and then blocks them. It has both a vendor provided blacklist and a local blacklist and can, based upon trends, classify a sender to the blacklist.
It sounds like your mainframe is probably using a non-public IP address and somehow your vendors blacklist picked up that address from a collection of blacklisted addresses that they probably collect from their customers to improve their list. It is not something you'll find in the communications server pubs. Lionel B. Dyck, Consultant/Specialist Enterprise Platform Services, Mainframe Engineering KP-IT Enterprise Engineering 925-926-5332 (8-473-5332) | E-Mail: [EMAIL PROTECTED] AIM: lbdyck | Yahoo IM: lbdyck Kaiser Service Credo: "Our cause is health. Our passion is service. We're here to make lives better." I never guess. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. - Sir Arthur Conan Doyle NOTICE TO RECIPIENT: If you are not the intended recipient of this e-mail, you are prohibited from sharing, copying, or otherwise using or disclosing its contents. If you have received this e-mail in error, please notify the sender immediately by reply e-mail and permanently delete this e-mail and any attachments without reading, forwarding or saving them. Thank you. From: "Morris, Carey" <[EMAIL PROTECTED]> To: IBM-MAIN@bama.ua.edu Date: 03/28/2008 12:44 PM Subject: Email blacklist A few nights ago we started getting this message when we tried to send emails from the mainframe to our Outlook email server: EZA5198I 03/25/08 23:25:23 2< 550 Denied by policy: Sender is listed on DNS-based RBL. The Outlook admin explained that we use several outside services to identify email from SPAM sites and, for whatever reason, one of those sites had identified the mainframe's IP as a SPAM'er. He said we should also be getting a message or email identifying the IP address of the service that had blacklisted us. The problem cleared by itself, presumably when the service corrected the problem, but I have not been able to find anything in the Communications Server manuals that talks about this. Has anyone else had the honor of being blacklisted and, if so, did they receive anything to tell them who had blacklisted them? Thanks, Carey Morris City of Fort Worth ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html