Email Filtering Review
Software keeps spam at bay

Email Filtering Review

Version 5.5 of Brightmails Anti-Spam software, released in December, has
improvements to better handle spam originating from open proxies, and
has improved URL-based filters.

New in the release are personal
blacklists and whitelists for users running Microsoft Outlook, and new
buttons for people using Lotus Domino client software to enable them to
report incorrectly blocked messages and unfiltered spam.

The
software is available for Windows, Red Hat Linux and Solaris 2.8/2.9
servers, and is also offered by third-parties as a service, and by
others in appliances. In each case, the spam definitions are updated
every 10 minutes from Brightmails datacentres. We reviewed the Windows
version using a twin 400MHz Xeon processor system, on which we recorded
an average 30 percent processor utilisation while the suite was idle.
Brightmail has priced its products by the number of users, so the number
or type of servers used does not affect the acquisition price.

For our tests we configured Anti-Spam 5.5 to work alongside the basic
SMTP mail server built into the Windows 2000 Server operating system.
The suite can also be used with any SMTP message transfer agent (MTA),
and a special version is available for use with Microsoft Exchange.

Brightmail said its software generates a very low percentage of false
positives one in one million messages incorrectly identified as spam. We
did not test this claim, but the downside of a low false-positive rate
is that such products are likely to allow more junk email to pass
through to the users mailboxes. With this in mind, the web-based
Quarantine tool should provide administrators with some relief because
it allows each end-user to manage their own spam controls.

Brightmail Anti-Spam 5.5 differs from many spam filters because the
suite does not include an MTA. While this will suit some firms, others
may be better off with a system that combines mail server and spam
filter in one package.

During setup, Brightmail installs the
MySQL database and Tomcat web server, which are both required by the
Quarantine module. The management interface uses Microsoft Management
Console (MMC), so it will be familiar to many Windows system
administrators. Built-in wizards made it simple to configure Brightmail
options such as the global whitelist and blacklist.

Integrating
Brightmail with the Windows SMTP service was also extremely easy.
Brightmail monitors standard Windows SMTP and post-categorisation event
sinks for incoming messages and, once it has processed them, it hands
the messages to the Windows SMTP service, which then delivers them.
Before putting our Brightmail system online, we only needed to specify
the domain names for which our system was handling mail.

We had a
little more trouble with the Quarantine module. This module stores
suspected spam messages in a special database, and users can configure
Brightmail so they periodically receive a summary of these messages.
Although it is installed automatically, the Quarantine web site does not
use the standard HTTP port, so some users might need a little training
in how to specify port numbers in a URL. Also, the Quarantine web pages
are not compatible with Microsofts Internet Explorer 5 browser, so many
firms would have to upgrade most of their desktop PCs before they could
use this feature. The Mozilla browser seemed to work well with the
module.

At present, Brightmails technical support is handled from
the companys San Francisco head-office, and is available only during the
US working day.

Infos zum Thema:

Brightmail