FREE OPEN SOURCE ANTI-SPAM

MailWasher Server is an open-source, server-side junk mail filter package for businesses of any size.

MailWasher Server differs from other open-source server anti-spam packages in that it offers a polished, well-integrated web interface and built-in quarantine management facilities. It is simple for administrators to set up and manage and easy for users to use the product on a day-to-day basis. In addition to fully supporting Windows Server/Exchange Server systems, Unix-based systems such as Linux and Solaris integrated with Sendmail and Qmail are also supported.

FULLY FEATURED AND POWERFUL

MailWasher Server is powered by users who report millions of spam emails daily to a central database (FirstAlert!) where spam is matched and processed in real time to instantly remove spam from users email. This means instant spam protection with minimal configuration and maintentance.

MailWasher Server plugs in to Microsoft Exchange Server, Sendmail and QMail for easy installation and administration and without the need for additional hardware or client side software.

When email enters MailWasher Server, it is first checked against global and individual whitelists and blacklists, then against FirstAlert! where the unique signature of that email is checked against a massive database of known spam. Finally, if enabled, the email can be checked against RBL's and bayesian filters.
At each point, if the email is determined to be spam it is either quarantined or marked as spam for later filtering.

Other features for Administrators include statistics, User management by integration with an Active Directory domain or LDAP server and end user controls.

SIMPLE FOR END USERS

End users can either access quarantined email via a browser to view and/or rescue blocked email at the administrators request, or a spam header can be added so that spam is sent directly to the end users spam folder.
This means users don't need to learn anything new or have additional software on their desktops.

FEATURES

• Instant protection against spam and phishing
• Maintenance free with FirstAlert!
• Privacy - emails never leave your network
• No downtime due to MailWasher Server - email is still delivered
• Plugs in to your mailserver - no extra hardware required
• Spam processing and blocking statistics
• Integration with Active Directory
• Simple Wizard-based installation, then works automatically with no configuration
• Simple for end users - Spam is automatically moved to quarantine or a spam folder

RECOMMENDED SETUP

To get the best results from MailWasher Server, we recommend the following antispam settings.

FirstAlert! Community Spam Filter - buy from $149 for 10 users.
Spamhaus RBL zen.spamhaus.org (free)

Using these two tools together will block almost all your spam.

Additionally, the trait based learning filters (bayesian filters) are very accurate and after a small amount of training (100 emails) your catch rate will be close to 100%. The filters will continue to be trained by FirstAlert! and your legitimate email.

We don't recommend training filters where the user base email content will be diverse, such as Universities.

REQUIREMENTS

Operating System:

• Microsoft Windows Server 2000 or 2003
• All Posix (Linux/BSD/UNIX-like OSes)
• Solaris

Email Server:

• Microsoft Exchange Server 2000, 2003 or Microsoft Small Business Server
• Sendmail
• Qmail

Memory: 256 MB minimum
Disk Space: 10 MB
Processor: 1000 MHz

ABOUT SPAM FILTERING

FirstAlert!

FirstAlert! is the first line of MailWasher Server's defense against junk mail. FirstAlert! is a known-message filtering service provided by Firetrust. It works by decoding the content of the message, computing a fully anonymized 'signature' - similar in appearance to a cryptographic hash, but designed so that small variations in the message content have little effect on the signature, providing a carefully controlled amount of 'fuzziness' in the message-matching process - and then checking that anonymous signature against the FirstAlert! servers.

The tight match settings used by the FirstAlert! servers ensure that the system's false positive rate remains low even with millions of active messages in the content database; in fact, no false positive due to signature matching has ever been observed. Finally, the pipelined FirstAlert! protocol makes communications fast and efficient.

FirstAlert! is provided by Firetrust as a paid service, but Firetrust keeps the cost as low as possible to make it possible for organizations of all sizes to take advantage.

Real-time Blackhole Lists

MailWasher Server supports both IP addressRBLs and SMTP envelope sender domain RBLs (RHSBLs). Support for message-content URL blacklists is planned for the near future.

Sender Address Blacklists and Whitelists

MailWasher Server offers both global and, optionally, per-user email address whitelists and blacklists.

Statistical Content Analysis

MailWasher Server's statistical content analysis filter combines both traditional word-based 'Bayesian' filtering and 'trait-based' filtering.

'Traits' are characteristics often observed in junk mail captured in the wild that rarely or never occur in legitimate mail - usually because the characteristics are produced by the commercial junk mail applications used by many spammers, or written in by the spammers themselves in an attempt to evade other junk mail filters. MailWasher Server detects these traits and considers them in addition to the message's words when performing statistical analysis of the message.

Traits are a very useful tool because they combine the filtering power offerd by manual rules in many other mail filtering systems together with the accuracy gained from having the traits trained on the actual mail received by the users - ensuring that, for example, the filter is quickly trained so that legitimate commercial mailings that also happen to express similar traits are not undesirably filtered.