SpamAssassin is a server-based email filtering application that attempts to identify spam messages. When identified, SpamAssassin simply marks the message as potential spam and then continues to deliver the email to your account as normal. SpamAssassin will NOT (by default) delete or move any email messages, but it will insert certain identifiers in the message header which allows you to filter the message using your email client's filters.
In the coming months, we'll also have a SpamAssassin module in our Account Manager so you can modify how SpamAssassin works for your account automatically.
SpamAssassin inspects the headers and body of an email message and determines the probability of the message being spam. SpamAssassin then marks the email message as spam or 'not spam', adding extra information to the headers of the email. This information can then be used as a filtering mechanism for your email client such as Thunderbird, Outlook, or our webmail system.
SpamAssassin uses a rule-based scoring system in which a variety of heuristic tests are performed on the email. For more information on the types of spam tests performed on an email message, please visit http://www.spamassassin.org/tests.html. Each test has a specified score associated with it. If the total score of the message exceeds the predefined threshold spam limit, the email message is then considered spam and tagged with the spam identifiers.
The default threshold for spam at Progressive Networks is currently set at '5'. It usually takes a number of tests to add up to a score of 5, and the tests that are run are included in the message header for you to view as well.
SpamAssassin is on by default for all paid and free accounts.
SpamAssassin evaluates every email message that comes to your account. If it thinks any email message is spam by scoring a '5' or higher, it will add a number of headers to the mail message letting you know. They will look something like this:
X-Spam-Flag: Yes X-Spam-Level: ******** X-Spam-Score: 8.518 (********) HELO_DYNAMIC_IPADDR,SARE_ADLTOBFU,SARE_ADLTSUB1,SARE_ADLTSUB2
The first header is 'X-Spam-Flag' and it is either a yes or no value letting you know that the message is either spam or it's not. In this case it's "yes".
The second header is 'X-Spam-Level' which is a representation of the score the email has received in asterisks (*).
The third header is ''X-Spam-Score' which contains the numerical value of the score along with the representation in asterisks, as well as the tests which returned a positive match for typical spam characteristics.
In addition to marking every spam message, SpamAssassin also add information to the headers to non-spam messages as well. That information will look something like this:
X-Spam-Flag: No, 0.612 out of 5. Tests: SARE_HTML_INV_CHARSET
Again, the X-Spam-Flag is present and contains three sets of information. The first is a boolean value of 'No' telling you the message is not spam, and the second is the score it assigned to the message out of the default threshold. In this case, the message got a score of 0.612 out of 5, which isn't high enough to make it a spam message. Finally, we also include the tests which returned a positive match for typical spam characteristics.
We are currently putting a module for SpamAssassin into our Account Manager that will let you filter messages on the server. In the meantime though, you can use your email client to create 'filters' or 'rules' to move messages that match the headers above to a special 'Junk' or 'Spam' subfolder of your Inbox.
You can also create a filter on your email client that will allow you to delete messages marked as spam, but Progressive Networks does not recommend this, as a non-spam message might get incorrectly scored and deleted.
Progressive Networks has a number of support options in addition to our FAQ's available for our members: