Ara Rubyan’s Best Free Articles

The following anti spam programs are effective, popular and (the best part) free!

eXpurgate

Expurgate is an effective, if unusual, anti spam program.

Here’s what that means:

You have to use at least two different email accounts to use eXpurgate. Your existing email address has to be set up to forward your incoming mail to eXpurgate where the messages get filtered. After that, the mail is sent to another account for distribution to you.

Beyond that, eXpurgate uses familiar anti spam techniques such as

Pros

• eXpurgate is easy to set up and maintain.
• Unlike a Bayesian filter, this anti spam program requires no training to reach optimum efficiency.
• Saves you download time and resources

Cons

• EXpurgate does not “get” your mail from a POP or IMAP account — you have to set up your email box to forward it.
• After filtering your mail, eXpurgate sends the mail to a second account of your choosing — and/but this address MUST NOT get into the hands of spammers…or else you are back where you started.
• EXpurgate’s spam filter rate isn’t as good as an anti spam program that uses a fully trained Bayesian filter

G-Lock SpamCombat

SpamCombat combines the personal approach of Bayesian filtering with the “two-heads-are-better-than-one” approach of DNS blacklists to capture spam very effecetively. It also uses content analysis to uncover bogus HTML that may be hiding real spam. All of these features eliminate a lot of spam at the server before you download it to your computer.

The downside to SpamCombat is that it only works for POP email accounts. Not only that: it cannot work as proxy, so you are required to check your email twice — first in SpamCombat, then in your email client.

SpamCombat makes the process of training the Bayesian filter a bit difficult by presenting you with an interface that is kind of cluttered-looking.

SpamCombat supports white- and blacklists through regular expressions — not exactly my favorite thing to do as it is kind of involved. Luckily, this isn’t a core function of SpamCombat and it works fine without it.

Pros

• Uses multiple blocking and filtering techniques for high success rate
• Uses Bayesian filtering
• DNS blacklists
• Can detect bogus HTML that hides spam messaging

Cons

• Supports POP accounts only,
• Cannot work as a proxy
• The interface is cluttered
• Message preview feature not the greatest not ideal

K9

K9 uses a Bayesian filter to find spam. As you know, you will have to tell K9 what you consider to be spam and what you consider to be good email. K9 will do the rest and put the spam in any folder you want. You can periodically check the folder to make sure K9 is not junking any real mail; if that is the case, you can correct K9’s filter easily so it won’t happen again.

K9 can also connect to a DNS blacklist for known spammers, although some users suggest that this won’t increase K9’s accuracy.

K9 works as a POP proxy so it works with just about any email software. The downside to this is that it only works with POP accounts.

Pros

• Works with any email client

Cons

• No remote administration
• No web interface
• Only supports POP accounts

MailWasher

Mailwasher deletes spam right at the server through a system of filters that use regular expressions (formulas that describe a series of words or phrases). It also uses black- and whitelists, relying on the information in the email header (sender, subject info, etc.). This makes MailWasher easy to use and maintain.

MailWasher lacks the kinds of scoring filters or Bayesian statistics that automatically adjust to spammers’ tactics. Another drawback is that it you can only use Mailwashwer on one POP account. Not only that: it doesn’t work with IMAP accounts. It also doesn’t work with Web-based email accounts.

Pros

• Mostly easy to maintain and use
• Uses black- and whitelists of senders

Cons

• Supports only one POP account
• Doesn’t use scoring filters or statistical analysis which requires you to perform some amount of maintenance

POPFile

POPFile is an email classification tool that can be used to identify and isolate spam automatically.

Using Bayesian filtering, POPFile will “learn” what you teach it about sorting and storing desirable versus spam.

POPFile can be used as an SMTP proxy before you mail server to filter all your mail. This means you can use it with almost any email client. If you use an NNTP news reader, POPFile can classify news items as well.

POPFile uses a web interface for configuration and correction of decisions about spam.

Pros

• Works via web interface
• Can be used as a POP proxy as NNTP
• Uses Bayesian filtering

Cons

• Can be a memory and CPU hog
• Not optimized for enterprise use

SpamExperts

First the good news: SpamExperts requires virtually no configuration out of the box.

Now the bad news: the occasional re-configuration sometimes requires a reboot.

Beyond that, SpamExperts is pretty easy to use. It uses a combination of checksum analysis and a Bayesian filter. Not sure why it runs so slowly sometimes. I do know that getting your mail is going to be a two-step process: first SpamExperts has to go get and then examine your mail. It can be configured to do this in the background. Then, you have to actually retrieve the good mail that is left.

SpamExperts will also quarantine any email it is unsure about. That way you can go in and have a look, training the Bayesian filter to recognize it the next time.

Pros

• Works without any configuration
• Supports POP and IMAP accounts

Cons

• Slow to process and filter incoming mail
• Re-classifying mail isn’t the easiest thing to do
• Cannot sort by spam score
• Changing some settings requires a reboot

Spamihilator

Spamihilator works as a proxy for POP and IMAP mail systems. This means that it will work with just about any email software and isolate spam before you download it.

It uses two techniques for catching spam: A Bayesian filter and something called Distributed Checksum Clearinghouse (DCC):

The basic logic in DCC is that most spam mails have several copies floating around. Any server using DCC that finds a spam email creates a checksum (adding up the basic components of the message and then creating a shorthand value). The server then posts this value to a central database. The next server receiving this email would get the DCC results and can more easily identify the email as spam.

The one thing Spamihilator doesn’t do is mark spam for further filtering via your email client. More than two categories of mail for automatic classification would be nice, too.

Pros

• Spamihilator can be used with any email client because it works as POP or IMAP proxy.
• Combines multiple techniques for filtering spam which makes it very effective.

Cons

• No remote web-based administration
• Will not classify and/or categorize your good email

SpamPal

SpamPal uses an “a la carte” approach for eliminating spam. This means that you can mix and match various different techniques:

• Blacklists
  With SpamPal installed you can choose from a variety of published lists of known spammer domains and servers. If you receive mail from one of these sources, it will be identified as spam and isolated.

• Whitelists (manual and automatic)
  This is a list of contacts that you decide are acceptable to receive email from and should not be sent to the trash folder. SpamPal will help you build such a list automatically (faster) or manually (more accurate).

• Bayesian filtering
• Content scoring

SpamPal works with any email program because it acts as a proxy.

Pros

• Uses Bayesian filtering as well as many blacklists
• Works as a POP and IMAP proxy so you can use it with almost any email client
• Includes SpamAssassin (a server-side anti spam program that uses content-matching rules, as well as DNS-based, checksum-based and statistical filtering)

Cons

• SpamPal isn’t fully immune to blacklist problems
• DNS blacklists are slow-performing and suck up a lot of bandwidth

© 2007 Ara Rubyan. This work is licensed under a Creative Commons Attribution-No Derivative Works 3.0 License. You have permission to use it if you include the resource information below.

For more info, visit Ara Rubyan’s Spam Blocker Central.

Ara Rubyan is experienced in training design and delivery and has been developing web based training for more than 10 years. His background in training coupled with his IT knowledge help him to ensure the seamless development of product user training.