Are you looking for a ‘Free (cost free) and Easy' antispam  or spam blocker solution for your organization that support multiple email domains?

Are your looking for a anti-spam solution can be deployed in your production environment for less than 20 min?

ESVA Email Security Virtual Appliance (ESVA) is a FOSS-based anti-spam solution  created by Andrew MacLachlan since year 2005. ESVA is a pre-built Virtual Appliance that runs on virtual machines. The latest version of ESVA can run on VMWare, run on Citrix XenServer, Microsoft Hyper-V and VMware platforms.

The development of the application has been stop for almost 2 long years to the day after the release of version 2058. I was so happy that current version 2060 is not available. To download the latest version please visit ESVA's GD official website.

The major components of ESVA are:

  • CentOS – Robust Red Hat-cloned Operating System
  • MailScanner – Anti-spam package for e-mail gateway systems.
  • MailWatch- Web-based  admin page for MailScanner
  • Postfix –  Email System
  • SQLgrey – Greylisitng Filtering
  • Webmin – Web-based  admin page CentOS and Postfix admin
  • ClamAV – Open Source antivirus
  • Distributed Checksum Clearinghouses (DCC)  & Vipul's Razor – Bulk Spam Mail detection
  • Pyzor – Spam detecting network
  • SpamAssassin  – Well-known spam filtering package for header,  text analysis, Bayesian filtering, DNS blocklists and filtering database
  • FuzzyOCR – Content and properties of images Filtering based on fuzzy logic
  • MailGraph – Graphical Mail statistics tools

Why I use ESVA?

The advantage of using ESVA are:

  1. Free in cost,
  2. robust system,
  3. filtering accuracy
  4. domain and sender black-listing
  5. domain and sender white-listing
  6. quarantine and release report (per user basis or per domain)
  7. easy to use and customized.

I've deployed self-customized version of ESVA in our datacentre since 2007 and it is still one of our best anti-spam solutions. Although, Bayesian filtering method require time to built on SPAM or HAM database. Overtime, ESVA's on mail filtering becomes more effective to distinguish between the ham and the spam compare to some commercial products.

We have 2 units of ESVA deployed at layer2 running our datacentre to take care of more than 500 domains and 10,000 volume of email per hour. Our ESVA is used for e-mail quarantine, anti-virus scanning, fuzzy OCR and Bayesian filtering.

However, a few important features that I think the author should include:-

  1.  No SMTP Authentication or LDAP integration
  2. No Subject Filtering
  3. No Keyword Filtering
  4. Incorrect GIF and JPEG filtering

Some of the above-mentioned weakness can be solved by scripts customization. However, I need to figure out the feature of each package and plug-in and file path. Current, I am compiling FAQ and customization configuration and hope that anyone using of ESVA can be benefit from it.

Nevertheless, ESVA is one of the most effective and powerful FOSS-based spam solution I ever deployed. It definitely will help your organization on spam issues. 

Source by James Edward Lee