Unfortunately, too many mail servers are configured to accept all mail, regardless of whether or not the recipient exists. Only then do they check for a recipient, and puke out an NDR. There are a *LOT* of misconfigured mail servers in the world.
Blocking NDRs won't work. Kurt On Tue, Oct 7, 2008 at 11:03 AM, wjh <[EMAIL PROTECTED]> wrote: > It shouldn't. a legitimate NDR should happen while the sending and > receiving SMTP servers talk to each other. legitimate sending server > connects to the receiving server and the receiving server accepts the > message or does not. Either way, it is communicating with the sending > server directly...just like if you telnet to your smtp server port 25 and it > gives you feedback. Backscatter email goes through spam server because it > isn't originating from your smtp server. The only legit bounces may come > for users who might have pop or imap accounts setup not to send through your > smtp server. > > There are probably others on the list that understand the protocols better > than me, so feel free to chime in. > > Bill > > > [EMAIL PROTECTED] wrote: > > If this could be done, wouldn't it also block legitimate NDRs? > > > -------------- Original message -------------- > From: wjh <[EMAIL PROTECTED]> > >> These types of NDRs drive me crazy. Here is one option if you have a >> pretty typical setup. Typical setup: incoming mail comes in through a >> spam gateway device/server, but outgoing mail leaves through your >> exchange server. All legit NDRs should be communicating directly with >> the sending smtp server. If an NDR hits your spam server, then it would >> be backscatter from spam. You could set your spam gateway to block or >> quarantine these false NDRs. They do the user no good anyway. >> >> Bill >> >> [EMAIL PROTECTED] wrote: >> > Exchange 2003 SP2. We occaisionaly have users who get a few NDRs over >> > a couple of days from reipients they did not send to because of >> > spammers spoofing t heir e mail address. At 12:15 I have a user who >> > began getting hundreds of NDRs obviously as a result of a spammer >> > sedning out a bulk email package. These are coming in so fast the user >> > is having a hard time keeping up with the deleting. Anyway to prevent >> > this crap? >> > Thanks. >> > >> >> >> ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ >> ~ http://www.sunbeltsoftware.com/Ninja ~ > > > > ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
