Idalis Anti-Spammer™ and ViDentify™ System
Pros - Identifies similar e-mail messages and viruses and compares their characteristics to see whether the sender is being randomized, or being sent from multiple open relay servers. Removes domains and raises spammer costs while also lowering their chance of revenues through permanent point of contact (URL, e-mail, phone number) filtering and site blocking. Only has to identify new spam characteristics daily (1% average of new spam, accuracy approximately 99.9+%) versus other "filtering" systems (100% of all unknown and changed spam, 95% accurate). Can report abuse complaints to spam website hosts, blocks illegally marketed websites (BrowseSafe). ViDentify, which is included in the Gateway product, can identify and contain e-mail based viruses faster than other manual based innoculation products.

Creates interconnected real time URL and spam "zombie" blocking filter across every Idalis customer. Every detection signature flagged as bulk is confirmed and organized by a human confirmation to prevent spoofing and ensure accuracy. Detects and blocks phishing or other scam emails with very little end user intervention.


Cons- The Idalis technologies are new and need proven in the large Enterprise before administrators have validation (and testimonial) to adopt cost/performance enhancing services.

Bayesian, Statistical Analysis, Pattern Matching, DNA Filtering
Pros - does good job of sorting spam from legitimate mail. Widely distributed with the core technology being free and many client side versions are available. These technologies act as a supplement to Idalis based technologies for spam without an identifiable point of contact.

Cons - "The Bayesian Effect" or endless game of cat and mouse. So long as an analysis filter can be broken or defeated spammers will send to it. Cannot prove to the "spammer" the message is being deleted even if it is. Machine learning can delete wrongly reported e-mail in the future (corpora poisoning). 100% accuracy requires user to review all bulk e-mail (time loss) and also requires end user configurations (user difficulty).

These types of filtering do nothing proactive to get rid of the sending or spammers causing the problem, making these technologies self-justifying. Can not ruin spammers and has proven over the last 10 years to have a reverse negative effect on internet e-mail. Too many variations in filters for "standardized" global effectiveness. The "Bayesian Effect" is the term given to the cause and effect relationship that happens when Bayesian or statistical filters are the primary technology used to combat spam and e-mail fraud. The Bayesian or Statistical filters actually generate more spam since they allow an 'acceptable' amount of spam to pass, which allows the spammer to still generate revenue, but in order to maintain his revenue - he has to send more spam and that increased overall level of spam has a greater chance of making it into an inbox. (counterproductive) and forces customer to purchase additional equipment to cover overhead.

Only 93-95% accurate in detecting and deleting spam daily. Cannot guarantee a message will be deleted if previously detected, including the spammer point of contact. Does not utilize URL filtering or other kill file technologies since these technologies have no means of insuring accuracy.

Challenge Response
Pros - Stops mail from reaching inbox unless authorized or confirmed by the sender. Works on server or client level.

Cons - requires recipient administrative time for senders who won't or can't confirm their e-mail address (time loss). Takes sender twice as much time to send first contact e-mail message. Surveys show request for sender to confirm e-mail address is "intrusive". Difficult to receive confirmation emails from legit companies who send automated e-mail (must require end user review time). Some systems can be authorized with an auto responder bounce back. Confirms actual address and could allow address spoofing with commonly used addresses. Requires user review time. Impossible to implement internet wide. Generates high number outgoing messages.

Reverse DNS Checking, Message Signing
Pros - free to use from respected vendors

Cons - is already helping legitimize signed spam messages being flagged by Bayesian filters. Domain reverse DNS addresses easily spoofed with lookup. Legitimate relaying harms messages (using own email with another server due to ISP restrictions). Won't work for many .cgi forms or mail forwarding. Vendors admit that reverse DNS checking cannot be end all to spam problem because of forging. Virus authors could use free available code to legitimize their infected messages right on the infected computer.

Relay Blacklisting
Pros - freely available non-profit donation based service for mail servers and anti-spam vendors. Rejects mail from servers that have been relayed through. Can block incoming mail before connecting.

Cons - Requires manual reporting or large sample to identify signature. Since 1998 has not decreased the amount of spam e-mail being send to computer users. Nightmare for network administrators who have been blacklisted and are now having their legitimate e-mail blocked.