Talking to an anti-spam provider and their first ISP customer, we learned how ISPs can help anti-spam software designers with feedback and data.

by Alex Goldman ISP-Planet Managing Editor [June 10, 2004]

Franklin, Tenn.-based anti-spam service provider SublimeMail would never have done what it has without the support of its first ISP customer, Huntsville, Ala.-based API Digital, a VISP provider.

It helps that a key SublimeMail employee is local to API. "One of their developers lives here in Huntsville. We had been evaluating several other solutions, until one day we had lunch and he sat down and said, 'this is what I'm doing,'" explains Scott Pell, vice president and general manager of API (and also a co-founder).

The first thing API provided SublimeMail was a massive number of e-mails for testing the anti-spam software. "When they needed e-mail to throw at the system, we provided them with several hundred million from the past several years," explains Pell.

The results are posted on the SublimeMail website:

e-mails filtered: 781,796,627
spam caught: 667,918,532
percent spam: 85.43%
false positives: 9

The software generally blocks over 90 percent of all e-mail, Pell explains. "For example, we have one ISP customer with 2,500 subscribers. They get 100,000 e-mails per day, and 90 percent of it is spam—literally 90 percent. SublimeMail reduces the daily load on the customer's server from 100,000 to 10,000."

A key benefit for API is that it was able to integrate the spam folder into its existing webmail service. "We use Procmail, with SquirrelMail for the webmail interface," says Pell.

That avoids a problem he noted with other anti-spam solutions. "If their pitch is to work, you have to either ditch the mail or offer the customer a second interface. I'll pick on Postini for a moment, but we could talk about any of them. My customers are rural Internet users. Webmail, outside of Hotmail, is a pretty big deal to them. With Postini, they now have a third interface to log into, and that's too many. Also, Postini offers knobs and whistles to adjust—so you can cut your own throat."

Technology
Sometimes it feels like there are 300 anti-spam companies selling various combinations of only several core technologies. SublimeMail doesn't do anything we haven't heard of before, but it does seem to do everything it should do, which is unusual.

It uses a rolling hash algorithm to catch known spam, with a second, similar algorithm to "catch the almosts," a necessity for any pattern matching engine ever since spammers' software (a.k.a. ratware) came bundled with the ability to make each spam slightly different (by as little as one character).

Pell says SublimeMail also uses the hatch to catch worms and viruses (malware), and that it creates the hashes faster than the competition.

The software also handles bounce spam. "People who forge e-mail addresses cause bounces," says Pell. "Also, some viruses forge e-mail addresses, and if you process the bounce, the spammer learns that's a real e-mail address."

Samuel Rainey, vice president for business development at SublimeMail's parent, Franklin, Tenn-based VC and incubator Think! Ventures, says the software is designed to handle 750,000 e-mails per server per day, though he notes that API achieves double that number.

Pell admits the company might be able to "fry eggs on its processor" but notes that most ISPs ride their hardware to the limit. "The harder you push the gas pedal down, the shorter it lives," he admits.

Pricing and availability
SublimeMail is available now. Pricing is about $1,000 per month with a $6,500 setup fee that includes one server, for ISPs with between 100,000 and 750,000 e-mails per day. Pricing rises depending on the number of e-mails per day that the ISP receieves.

Entities that receive less that 100,000 e-mails per day can use SublimeMail's hosted solution, for a monthly fee.

—End