SpamAssassin technology—killer!
For now, SpamAssassin is among the leading anti-spam technologies available and is familiar to most ISPs. It compares the message to hundreds of tested rules, then checks to determine of it is spam or just a message from mom telling you to clean your room. Each message is given a score based on the likelihood that it is or is not spam. The spam-scoring process is completely automatic, but the scoring thresholds can be adjusted and customized. Additionally, it integrates directly with the Bayesian filter and provides spam message and header reporting.

New in version 7.5.3 is Sender Policy Framework (SPF) and Spam URI Realtime Blocklist (SURBL), which are the current 'big guns' in the war on spam.

SPF is a key weapon against email spoofing, in which a spammer forges the header so a message appears to come from another person or location. Spoofing is a good way to get unsuspecting users to open and respond to a message. A growing number of organizations publish SPF records for their own domains and use SPF to distinguish forgeries from real email sent by other domains. Published SPF records include mail details such as authorized senders and mail server IP addresses.

Using SPF, the receiving server verifies the authenticity of each sender's FROM email address by performing DNS queries via the published SPF record to confirm that the sending server is authorized to send mail for that address. This entire process is done automatically by VisNetic MailServer.

Support for SURBLs allows for the filtering and blocking of messages based on the URLs of spam domains that appear in the body of a message instead of just those that appear in the FROM address field.

They have also included a Challenge-Response mechanism, which Deerfield claims is 'a foolproof spam blocking method, known to block 100 percent of computer-generated spam.' I wouldn't go quite that far, but it is effective.

If the other filters (SpamAssassin and Bayesian) don't catch the spam, then a challenge message, using 'black and white' lists, is sent to the message originator. If the user clicks on an embedded link and enters the displayed code, their message and all of their future messages will be allowed. Email from addresses which are 'white listed' are delivered, those on the 'black list' are deleted.

The Challenge-Response database, 'black and white' lists, and spam detection levels can be selected and maintained individually by each user via the WebMail interface.

The WebMail interface has a number of other new features and capabilities, including a spell checker, the ability to import and export an Outlook address book, and user-controlled certificate settings. By designating the mail server, username and password in an 'accounts' section, users can also download messages from other accounts on different servers into their VisNetic account.

Spell checker gets a Bronx cheer
Although it does work, I was not impressed with the Spell Checker in the WebMail interface. It does identify many misspelled words, but not all of them. For example, it did not see a problem when I entered 'iis' instead of the word 'is.' On the other hand, it does seem to understand some 'New York-isms.' It found no problem with things like 'doily boid' but didn't like 'byrd,' and it liked 'daws' as well as 'doors.' When it comes to spell checking in the VisNetic MailServer, my advise is to just fuhgeddaboutit.

A GroupWare feature (available for an additional license fee) lets users in a designated group share calendars, tasks, events, etc. and even publish this information on a website. Features include private and public calendaring and task lists, an event system with reminders, and a shared address book.

The one drawback is the lack of a global calendar that can be shared by everyone in a group. Allowing users to post to a global calendar would save the trouble of having to view several individual calendars when scheduling a meeting or event. Although this feature is not available, Deerfield's product manger says it 'will be added.'

GroupWare is an add-on available at an additional cost ($325 for a 250-user license) but it's a useful tool for groups who need to coordinate events and calendars and it can be a good way for the ISP to attract additional revenue.

Another nice addition in the latest version is the instant messaging (IM) feature which allows for secure communications between users and is compatible with the Jabber open XML protocol. When he first looked at it, one of the people on our testing team had a hard time understanding why anyone would want this capability since it is available for free from MSN, Yahoo, or AOL.

On further examination, the reasons were obvious. Besides not having to look at the annoying pop-ups from those public services, the Deerfield approach provides for secure, private messaging between individuals and groups It's great for multi-user chats, conferences, and private file transfers. VisNetic's IM server can also be enabled, via a gateway, to work with ICQ, AIM, Yahoo and MSN IM servers. Any jabber-compatible client can be used with the IM server.

Deerfield is also 'working on' the documentation for VisNetic MailServer. The user's manual (electronic) covers the basic functions, but it leaves out some of the more sophisticated features. During testing, we were continually finding things that were not adequately covered in the documentation. Hopefully, the next version will address this shortcoming.,

VisNetic MailServer 7.5.3 has a few flaws, but overall it's a strong, reliable performer with lots of features that you can install and then fuhgeddaboutit.

Pricing and availability
VisNetic MailServer 7.5.3 is available now.

Requirements for 1-50 users (a larger user base will require more system resources):

• CPU: PII 750Mhz
• Operating System—Windows 95/98, ME, NT4 Server and Workstation, XP, Win2000, Windows2003
• RAM: 64 MB RAM (Over 50 users, 128 MB. Over 2000 users, 256 MB. Over 5000 users, 512 MB)
• Disk Space: 30 MB, additional space for any mail to be stored

Cost: (VisNetic MailServer Pro with AntiVirus & GroupWare Plug-ins)

• 50 User License: $1,160.00
• 100 User License: $1,380.00
• 250 User License: $2,040.00
• Unlimited User License $3,540.00

—End

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