• Matching of messages against a "white list" which permits a message through, and a "black list" which flags the message as spam.
• Black list entries can be absolute (if a message contains the term it is deemed spam) or score-based (the word or phrase has an associated "score", and the total score for the message is compared against a "trigger level" to determine if it is spam); both types of terms can be intermixed in the black list file.
• Can return a message to the original sender with instructions for overriding the block (so that persons who are victims of "false positive" hits can still email you.)
• Can either throw away the flagged spam, or alternatively, for those who MUST have all email messages in an organization, redirect it to a "default" spam mailbox at that domain.
• Augments the "anti-relaying" checks performed by other mail software, strictly refusing to handle any message that is not intended for a domain that is "local" to the incoming system.
• For financial sites which are running on their own "real" machines (e.g. PayPal, etc) can perform absolute blocking of phishing emails. That is, the system can be configured to simply refuse to pass on email claiming to be a "PayPal" message unless the email actually originated on a PayPal server! If you are tired of "phish", this is the one solution that actually works.
• Operates in real time while email is being actually sent, as opposed to a "store and forward" model; this gives the system access to the actual connection information, which is critical to determining the real source of an alleged message aimed at your server.
• Automatically rejects attempts at source-routing email messages (a means sometimes used to get around the normal "anti-relay" checks that many SMTP mailers employ!)
• For systems operating in "team mode", where the user's home directory and limited authentication data is available to the system, can use a user-customizable form of the white and black lists, along with a user-customizable "return" mail file, with system defaults for any which the user does not wish to specify. The system "black list" can be appended to, if the user would prefer, allowing even more flexability.
• Includes a CGI program that allows easy, no-Unix-command-line maintenance of the configuration (black list, white list, and return files), both for the system level defaults and, for systems running in "team" mode, for each user. Now your users can edit their own specific spam blocking instructions, with no knowledge of Unix necessary, and can see what the system default files are allowing and refusing.
• Keeps full logs of all actions taken on incoming email messages through the system log facility and, optionally, when run in "team mode" can write a log for all interdicted spam for each individual user. You have complete accountability with Spamblock-Sys - no surprises!
• Logs "spam" and "white list" hits in the message HEADER as well as at the tail of the message body to permit easy inspection by users of exactly what the system did, and why.
• When run in "team mode" will handle pager forwarding internally for users who wish to forward messages to cellular phones or other email-enabled paging systems based upon user-defined criteria. Don't buy two software packages when you only need one to do both jobs!
• Very high-performance - able to handle extremely high volumes of traffic. Spamblock-sys is typically limited only by the final delivery system's throughput.
• Actively being supported - if you have questions, or even want someone to install the software for you, it will be handled - remotely - at a very reasonable cost.

How is Spamblock-Sys different than the others?

• PROVEN effectiveness. Blocks 99% or more of the spam when configured to be "fairly aggressive", while blocking almost NO legitimate email and, for correspondants who read an original bounce they receive, ZERO of their subsequent communications.
• Does not rely on any outside services or servers. Nearly all other spam blocking solutions rely on outside servers or lists, such as the "RBL" or other "black hole" lists. This is a bad design decision, as the spammers can attack those sources, vastly slowing down the performance of your mail system, rendering the interdiction system useless or even causing it to crash. In addition, the spammers have figured out how to get around this problem by varying their "injection point", making the black hole lists less effective. At best, a "black hole" list based system might catch 50-75% of the spam. Effectiveness under 90% is worthless; unless you can block nearly ALL of the spam you may as well just hit "delete"!
• Can provide 100% protection against "phish" for designated sites.
• Has very low maintenance requirements. Unlike most spam blockers you do not need to do much once you have "stabilized" your spam blocking list to keep Spamblock-Sys in tip-top shape.
• Is computationally cheap to operate. Complicated "evaluation" criteria touted by some competing products sound good, but is computationally expensive. This may be ok for low volume users, but it definitely is not ok in high volume environments! Spamblock-Sys requires a fraction of the computational power of your mail server - in cases where your mail system is running on a Unix machine, you can even run Spamblock-Sys on the same system as your mail delivery without significant CPU impact.
• Provides a "challenge-response" environment for email that is "accidentally" interdicted in error, yet will challenge a given sender only once. Once that user has authenticated their transmission to you as coming from a real human being, they will no longer be bothered.
• Allows challenges to be responded to either by email or via a web-based interface.