Bounce Messages

Bounces are messages, officially called non-delivery reports (NDR) or delivery status notifications (DSN), that are generated by a mail server to report on the delivery status of an email message.

Problems arise with bounces if they are sent by a mail server to a non-local recipient. If a message did not originate locally, then a mail server cannot know for sure if the address it is sending the bounce to is forged or not. This quickly leads to unsolicited “backscatter” (or more rarely “outscatter”), sent to sites that never originated the email.

Quite often a spambot, spammer or viruses will use your email address to send out spam messages and because the email is purported to be from your email address, you will receive the undeliverable messages.

This type of spam is inconvenient only to you as you can receive as many as several hundred bounce messages in a short period of time.

Anatomy of email backscatter.


But how can they send an email from my email address?
A spammer will set up a server somewhere and will create an automated email system and will simply enter any email address they come across. Its possible and very simple to do. The common word for this method is "spoofing" your email address.

Is there a problem with the Elkhart.com Mail Security?
They don't actually send via our server network, they can't do that unless they have your username and password (which is why its important to have secure passwords!) and even then our server software monitors the number of message going through our servers, so if a spammer tries to spam via our servers they will get caught straight away.

But can the spam filters not block these bounces?
Yes and No. Some bounces can be stopped via filtering. Epic Touch has setup filters to identify possible non-legitimate bounced messages. These messages will be identified with [BACKSCATTER?] prefixed on the message's subject line and the email will be moved to the Epic Touch customer's web-based JUNK E-MAIL folder.

The Backscattering filters are not 100% accurate. Some bounced messages may make it into your email client inbox and some legitament(false-positive) emails may be tagged as BACKSCATTER and be placed in the web Junk E-mail folder. You can learn more of the use of the JUNK E-MAIL folder and how to deal with the false-positve emails here.

(Thanks to Craig at 123marbella.net for most of this information.)
http://www.123marbella.net/kb.html#6