We might be talking about something else here, it isn’t an rdns check to avoid creating backscatter. It is a system to prevent your users from getting it if they are spoofed in the ‘from’ of a spam run. The Cuda acts as your outgoing mail relay and as it passes the email it tags all outgoing email. It also acts as your incoming MTA of course…..when it gets an NDR from the outside world it then checks to see if that NDR matches a message sent by your org using that tagging system. If it doesn’t match it rejects it. It flat out kills incoming backscatter when your user’s ‘from’ is used to forge a spam run.
http://www.thefreelibrary.com/Barracuda+Spam+Firewall+Rejects+Invalid+Non-Delivery+Report+%28NDR%29+...-a0183406988 From: Mark Tibbet [mailto:m.tib...@gmail.com] Sent: Wednesday, June 02, 2010 9:15 PM To: MS-Exchange Admin Issues Cc: MS-Exchange Admin Issues Subject: Re: Several NDR's All they are really doing is a rdns check to prevent spoofing. Most mta's should be capable. The only one if found that doesn't is message labs. Just my .02. Regards, Mark Tibbet Systems Engineer Enterprise Networking Solutions, Inc. mtib...@ens-inc.com<mailto:mtib...@ens-inc.com> Http://www.ens-inc.com On Jun 2, 2010, at 4:37 PM, Richard Stovall <rich...@gmail.com<mailto:rich...@gmail.com>> wrote: Totally agree about the Barracuda spoofing protection. I use it and it's wonderful. I've had zero reports of backscatter problems since implementing about a year ago or so. <furiously knocks on the closest wooden object> On Wed, Jun 2, 2010 at 10:56 AM, Kennedy, Jim <kennedy...@elyriaschools.org<mailto:kennedy...@elyriaschools.org>> wrote: Some spam filters can help. Barracuda for example can be set up to relay your outbound email and it keeps a record of your outbound email message ID's. You then also use the Barracuda for incoming email. Then when it gets an NDR it checks it against that message ID list, if it isn't on that list it rejects it. -----Original Message----- From: Brent Zalewski [mailto:bzalew...@comcast.net<mailto:bzalew...@comcast.net>] Sent: Wednesday, June 02, 2010 10:29 AM To: MS-Exchange Admin Issues Subject: RE: Several NDR's As I read through all the articles on this I really wonder what if anything can be done. Some articles say to report this and other say just to ignore it. What really is the best solution , if any? Thanks
