O/S Antispam software shows its roar

Spam has mutated, getting nastier and more prolific over the years, but CanIt-PRO has kept pace and blocked it out for one southern Internet Service Provider.

Almost three years ago, Mississippi-based ISP Dixie-Net decided to implement Roaring Penguin's CanIt-PRO version 2.0 to handle it's growing email spam problems. "Our users had been clamoring for a solution to the spam problem for months. We evaluated all the options, including open-source products, paid services, and other software solutions, said Chris Marsalis, then Vice President of Operations.

"Back then we tried other solutions including real-time blacklists, but as spammers got smarter we had too much incoming spam to handle effectively... The Roaring Penguin product was the only one that offered the type of granularity we needed to satisfy our customers."

Marsalis is currently the Director of Operations at Dixie-Net and has overseen the installation and upgrade of several versions of CanIt-PRO, now operating on version 3.3.7. With the growth and success of Dixie-Net and the constant evolution of spammers has come an increased reliance on the spam filtering tool's clustering capabilities. Explains Marsalis, "The server farm has grown in conjunction with our need for multiple filters distributing network bandwidth and processing power.

From the beginning things went well, with CanIt-PRO automatically blocking the majority of existing spam. Over the past three years, the spam volume has increased. Initially CanIt-PRO was running on only one server, but the raw size of the database quickly required more hardware processing power.

The Dixie-Net anti-spam cluster has expanded from that initial one server to six servers to cope with the load, but the increased size of the cluster has not increased the workload. In fact, CanIt-PRO has reduced the workload. CanIt-PRO's automatic updates reduced system administration time. Marsalis says CanIt-PRO also took the system maintenance time down from about 15 hours per week to "just a few hours every couple of weeks".

Change is constant in an ISP data centre; the increased volumes also meant updates to the software. Over Roaring Penguin's history there's been a constant arms race with the spammers; when the spammers invent a new technique, Roaring Penguin must immediately provide countermeasures. "Moving through several versions of the filter has usually been a painless process, says Marsalis.

Dixie-Net worked hard to find the default global spam settings suitable for the majority of their customers, but still allow flexibility at the individual user level. "Most of our clients are going to stay with those default settings, recalls Marsalis. "Users can interface directly with the filter and specify their own settings. Also, for a minimal fee, more advanced users can have access to the Dixie-Net Expert Interface which allows more detailed email filtering settings.

As well as utilizing CanIt-PRO for email spam filtering, Dixie-Net also uses the highly-regarded ClamAV anti-virus scanner (available as part of the CanIt-PRO system) to help filter out harmful viruses for the company's employees and 10,000 residential and business customers. ClamAV's frequent automatic updates often lead the anti-virus industry in timeliness.