Spammer tactics of circumventing filtering

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Articles & tutorials Backup & Archiving Email Clients Mobility Operating Systems Reporting Tools Security Antispam Antivirus Reports Server Administration Smart Setups Clustering Virtualization Studies & Benchmarks Support Services Web Integration Messaging news Axigen Presents Itself as a Fully Grown Messaging and Collaboration Platform with Version 8 Bucharest, Romania – March 31, 2011 – Axigen... Axigen Enters Indonesia through MTI Bucharest, Romania - February 17, 2011 - Axigen... Experience the Axigen Ajax WebMail with Calendars, Tasks and Notes The Axigen Team (http://www.axigen.com) has added calendars, to do... Upcoming events Switching from Free Open... AXIGEN (www.axigen.com), the professional messaging solution...	Spammer tactics of circumventing filtering Submited by daniel.toma, on 2007-12-03, in Antispam This article will focus on the tactics used by spammers to successfully deliver a mail message to the mailboxes on your server, despite any implemented sorting or blocking filters. Introduction As you may have noticed, there are some spam messages that always seem to defeat the filters and sorting mechanisms of your server, thus being successfully delivered to a mailbox. The most used tactic is based on the possibility for the sender to easily craft messages by modifying the message headers. This tactic is the base on which all spam messages are founded. This means that a spammer can forge the source of the message to disguise and conceal information about him. Below, I will describe some of the tactics spammers use to modify the headers, in order to ensure that messages are still delivered. Tags: anti-spam, filter, filtering, filters, message, messages, sender, server, spam, tactic, tactics, used comments (0) \| email this \| \| printable version Rating: Page 1 of 2 Next page » Leave a comment Full Name * E-mail * URL: Note: all fields marked with (*) are required Comments (0) To: Subject: Body: Verification code:	Why Register? Already a member? Blacklist monitoring alerts Signup for our real-time monitoring service and receive email notifications each time one of your IPs gets blacklisted. Mail Server Operating System Poll .01 What OS do you use for your email server? Linux Windows Other .02 How many mailboxes do you currently manage? 1-50 51-300 300+ .03 Would you like to comment upon the choosing of this particular OS? DNS Tools Get IP status, owner and location, obtain its corresponding hostname or check specific ports. Ping Statistics Reverse DNS Lookup Whois Info (IP owner) GeoIP Information Check Port Open Relay Test Test if your mail server is an open relay for spammers. Blacklist Checker Check if your IP is listed in DNS based email blacklists (DNSBL)