Friday, July 06, 2012, 09:20
Solution ID: 00000146
What is E-mail Backscatter, also known as outscatter, misdirected bounces, blowback or collateral spam? How can this affect my PerfectMail server? What can I do to prevent E-mail Backscatter? Is this an issue with my PerfectMail server?
Backscatter is incorrect automated rejection (or bounce) messages sent by mail servers, usually resulting from incoming spam. Such messages are viewed by the recipients as a form of spam, since the recipient is (by definition) not the originator of the e-mail being rejected.
Backscatter usually occurs because worms and spam messages forge their sender address (often with legitimate e-mail addresses). Mail servers configured to send Non Delivery Reports (NDRs) will incorrectly bounce the message back to the forged sender address.
Mail servers that generate email backscatter can end up being listed on various DNS Black Lists, and be in violation of the Terms of Service of some Internet Server Providers.
PerfectMail does not make use of Non Delivery Reports (NDRs), rather it uses SMTP Rejection Notices. These rejection notices are exchanged during the SMTP mail exchange; when e-mail is being exchanged between mail servers. PerfectMail is able to give notification during the e-mail exchange because it is a Live Filtering Solution. PerfectMail analyzes, filters and responds to e-mail in real time, during the message exchange. This guarantees that PerfectMail sends a rejection notification and that the sending server received it; which is implicitly the correct server to send the notification to. By definition, such messages are not Backscatter.
Tags: e-mail, backscatter, bounce, non delivery report, ndr, rejection notices, outscatter, misdirected bounces, blowback, collateral spam
Link to this article: kb/email_backscatter
Updated: Friday, July 06, 2012, 09:20
-- David Rutherford