SpamAssassin is an automated mail filter or software that helps to block spam or unsolicited commercial e-mails. It is basically an anti-spam tool that works on the back end of your email server and determines the email as spam as soon as it hits the server.

SpamAssassin, integrated with your mail server, uses a variety of spam-detection techniques that include DNS-based and fuzzy-checksum-based spam detection, Bayesian filtering, external programs, blacklists and online databases to automatically search through your email for the tell-tale signs of spam. You can set your own personal preferences too to define which emails are identified as spam and which are not with a simple point and click interface. It can also be configured to delete mails marked as spam automatically.

This software has been found to effectively eliminate 98% of all SPAM messages. Its performance depends on the individual configuration, which can be tuned according to the unique requirement of each website owner.

One important point to be kept in mind is that SpamAssassin doesn't block spam. Instead, it tags messages as probable spam by changing the Subject line and message headers. So it identifies probable spam e-mail, but the choice has to be made by the user as to what needs to be done with spam. You can add rules in your e-mail software to delete identified messages or, move them to a folder for later review.

SpamAssassin is disabled by default and it should be activated as soon as you login for the first time or when you create an email account. In order to enable or disable SpamAssassin:

1. Log into cPanel.

2. Click on the SpamAssassin icon in the Mail section.

SpamAssassin in cPanel

3. Click on Enable SpamAssassin in the gray box, to enable it; or click on Disable SpamAssassin to disable it.

Enable/Disable SpamAssassin

As per the option selected, a confirmation message will be displayed on the next page stating whether SpamAssassin was either disabled or enabled.

Confirmation Message- SpamAssassin Enabled/Disabled

Features of SpamAssassin

  • Flexible: SpamAssassin's logic is encapsulated in an abstract, well-designed API and so it can be integrated anywhere in the email stream. The Mail::SpamAssassin classes find usage on a number of email systems, like Postfix, procmail, gmail and many others.
  • Easy to extend: As configuration and anti-spam tests are stored in plain text, configuration and adding new rules become easier.
  • Adaptable: SpamAssassin can adapt to each system's email environment, learning to recognize which senders are to be trusted and to identify new kinds of spam.
  • Wide-spectrum: SpamAssassin identifies spam signatures by employing a broad range of network and local tests. This makes it harder for spammers to identify a single aspect which they can craft their messages to work around.
  • Easy Configuration: SpamAssassin needs very little configuration; there's no need to update it continuously with the details of the mail accounts, mailing list memberships, etc. Once configured, user and site-specific policies can then be applied against spam. Policies can be applied on both mail servers and later using the user's own mail user-agent application.

SpamAssassin's Spam Score Limit

Each incoming mail is assessed by SpamAssassin on a score of 0 to 10. The score is assigned depending upon the mail's spam characteristics that are calculated through various algorithms like DNS-based and fuzzy-checksum-based spam detection, Bayesian filtering, external programs, blacklists etc. You can also blacklist up to five mail addresses from which you don't want to receive mail.

SpamAssassin considers emails with a score of 5 to be spam by default. However, it is possible to adjust the limit of the spam score according to the account owner's preference. In the Filters section, select the desired spam score limit from the Score drop-down menu. Lower the score, stricter is the filter.

1. 0 translates to every incoming mail being marked as spam.

2. 5 is the default setting

3. 10 means all incoming mails will pass through with none marked as spam.

The last five fields are provided for whitelisted mail addresses. You should whitelist those addresses that send mail which is often tagged incorrectly as spam.

In case, one is unable to set a spam score limit through the Filtersdrop-down menu, the method given below can be used to change the default score:

1. Click on Configure SpamAssassin under SpamAssassin Configuration.

2. Enter your preferred value in the required_score field.

3. Click on Save at the bottom of the page.

Auto-Delete Spam

The messages that meet or exceed spam score limit can be deleted automatically by the auto-delete function. This function can be enabled in the Filters section by clicking Auto-Delete Spam and it can be disabled by clicking on Disable Auto-Delete Spam.

However, if auto-delete is enabled, you could lose emails that are not spam in case SpamAssassin is not configured properly.

Organizing Spam through Filters

For utilizing SpamAssassin to its full potential, users are recommended to set a Message Rule /email filter in their mail client. Emails that are determined to be spam will still be delivered in your inbox. Spam will be marked as "****Spam****" in the subject line. On setting up filters, users can sort the mails and have all messages labeled as spam placed into another folder for reviewing them at a later stage. This will ensure that junk mail remains out of inbox.

In order to filter emails with SpamAssassin:

1. Log into your webmail.
2. Here, create a folder called Spam.
3. Exit webmail.
4. In cPanel's Mail section, select the User Level Filtering icon.
5. Click on Manage Filters next to the appropriate user.
6. Click on Create a New Filter following which you will be taken to a new page.
7. In the Filter Name field, create a name for the filter (like SpamAssassin or whatever desired).
8. Under Rules, select Spam Status from the first drop-down menu.
Note: If this option is not available, check to make sure that Spam Assassin is enabled.
9. In the adjacent drop-down menu, select begins with.
10. In the large, blank box below the drop down menus, type the word Yes.
11. Under Actions, select Deliver to folder from the drop-down menu.
12. Click on Browse and select the Spam folder.
13. When finished, click Create.

Now, IMAP can be used to subscribe to the new Spam folder.

ZNetLive offers SpamAssassin free with its classic dedicated servers, zoom dedicated servers, VPS, reseller, SSD and shared hosting accounts. ZNetLive's Reseller hosting customers can use SpamAssasin for themselves and can pass it on to their end customers as well as a value added offering to generate additional revenue.