What’s New in PreciseMail Anti-Spam Gateway v3.1

Archive: What's New in PreciseMail Anti-Spam Gateway v3.0

Advanced Infrastructure (AI) phase 2

The Advanced Infrastructure (AI) module provides a scalable backbone for organizations that have deployed multiple high traffic email systems. It allows organizations to easily manage filtering distributed among multiple MTAs. Sharing data among many systems simplifies both management and end-user access. Administrators can run AI in simple mode, which is a basic client/server system with one master server, and one or more clients who depend on it. Advanced mode allows cluster tasks to be distributed across multiple systems.

AI Phase 2 replaces all the functionality that is currently in Data Synchronization Cluster module. Quarantined and discarded messages from one or more systems running PreciseMail may be coalesced onto a quarantine server and/or discard server.

Figure 1 – AI Web Configuration

Sender Policy Framework (SPF)

SPF (RFC 4408) prevents email senders from forging email addresses, reducing phishing attempts. It allows the owner of a domain to specify their mail sending policy, i.e., which mail servers they use to send mail from their domain. This feature can be enabled in PreciseMail’s enhanced web-based administrator interface.

Spam Filtering Improvements

The following new features can be configured in PreciseMail’s enhanced web-based administrator interface.

• Tarpitting is the practice of slowing the transmission of e-mail messages sent in bulk as a means of thwarting spammers. The intent is to maintain a high quality of service for legitimate users while making the sending process impractical for spammers, who -- because of low response rates -- must be able to send vast volumes of messages quickly and inexpensively. PreciseMail allows administrators to specify the number of invalid RCPT TO: commands per session that are allowed before tarpitting is active and the number of seconds that each RCPT TO: response should be delayed.

• Received: header DNSBL Support - Integrated (as opposed to proxy) installations of PreciseMail may now check remote senders against DNS blacklists. The Received: headers are analyzed for IP addresses, which are then checked against the configured DNS blacklists.
  
  
• URI DNSBL Support - Domains from URIs located in message bodies are checked against the configured DNS blacklists. PreciseMail confirms that the domain is associated with a spammer via one or more block lists.

• Reverse DNS Lookups on domains specified in URI in the message bodies. Spam domains often do not have reverse DNS domains defined.

• Verify Mail From (VMF) Performance Improvement - The VMF module dynamically checks the sender’s address for incoming email to make sure it’s valid. This address, also known as the envelope MAIL FROM: address, is often forged in spam messages and frequently specifies bogus email address (i.e., you can't actually send mail to the address). VMF checks may now be done locally instead of through the Process Software data center, which improves the overall performance of the feature.

The Anti-Relay option prevents third parties from sending or receiving email messages that are not for or from the local host. PreciseMail will verify the MAIL FROM: addresses purporting to be from a domain for which local addresses are defined. This will prevent forged email addresses from those systems from being accepted. Sites can supply a shareable image for customized address verification against third-party sources, such as an LDAP server.

Sites with high web interface traffic may wish to continue using a full-featured web server (Apache), but smaller sites may choose the simplicity of using the integrated HTTP server.

Administrators can now completely configure and manage PreciseMail using the web interface. The interface includes the ability to edit various configuration files from within the GUI (see Figure 2) and to configure anti-relay, reverse DNS URI filtering, DNSBL (see Figure 3), Tarpitting, SPF (see Figure 4), and the AI clustering component (see Figure 1).

Figure 2 – Web-based Configuration

Figure 3 – DNSBL Configuration

Figure 4 – SPF and Tarpitting Configuration