Got spam? Run a mail server? Like saving time & money?
The VMware Virtual Appliance Marketplace is a useful resource for a variety of specialized virtual machines. Some free, others for-fee, each built & customized for a specific role. Many of these can be downloaded & deployed in less time than their equivalent physical counterparts.
One of the virtual appliances which yours truly has been running for several years is ESVA, Andrew MacLachlan's Email Security Virtual Appliance. MacLachlan created and has maintained ESVA, with the help of community members, since roughly May 2005. Putting ESVA between my mail server and the intertubes was, in hindsight, an excellent decision.
From the ESVA homepage:
ESVA was born out of a need for organisations to have a cost-effective email virus & spam scanning solution. There are other commercial products out there, but these are often too expensive for small organisations to justify, or the existing free products are beyond the abilities of these organisations. ESVA is simply a pre-built and easily configured email scanning (security) Virtual Appliance (ESVA) that will run on VMware Workstation, Server, Player or ESX Server. The idea is for the appliance to be pretty much set & forget with an easy to use interface so that users don't really need to know how to use the underlying Gnu/Linux.
Looking under the hood, you'll find a noble collection of FOSS components, including:
ESVA is customizable, whether you want to add a SpamAssassin plugin, or host multiple domains. Once ESVA is up and running, it's like any other (*nix) box, without the time spent to build, configure & deploy. ESVA is also easily updated by running esva-update from the CLI.
ESVA excels in two key areas: first, it does an excellent job filtering right from the start. Second, it can be deployed easily in just minutes. What's the true litmus here? In this arena, the ultimate measure of success and the highest possible praise is this: anonymity.
ESVA works so well, you could easily set it & forget it.
As questions arise, you can use either the ESVA forums as a resource, or the respective FOSS component's community. The ESVA forums include custom code for authenticating MailWatch users against Active Directory via LDAP, and information concerning Master-Master replication for clustering (others have simply deployed two separate ESVA's in a production environment, which seems far simpler).
For the current release of ESVA (2.0.5.x), MacLachlan estimates that, "A 2 proc VM with 1GB mem running 10 MS children should be able to process 10-20,000 messages / hour."
ESVA is a cost-effective, well-designed, low-maintenance, easy to use & deploy SMTP filter which offers some impressive features. Often compared to commercial and even enterprise-class SMTP filtering solutions in the ESVA forums--the testimonials speak for themselves. Depending on your budget and mail volume, ESVA is worth looking into.
ESVA is available via OVF, FTP and intermittently via BitTorrent. A Xen edition is also available.
On a side note, if you'd like to test ESVA outside the office on a "bare metal hypervisor," (*shakes fist and curses the marketing dept.*), the free ESXi 4 works on many desktop SATA controllers, natively.
Leave the Spam to Hormel.