As part of our continuing fight against spam we have recently implemented new spam filtering across all of our email services. This free service uses SpamAssassin & Reverse DNS Blacklisting to identify spam emails. Although no spam emails are deleted its easy to setup an Outlook rule to move them all to a folder or delete them if you wish.

X-Spam-Flag filter
An X-Spam-Flag filter will catch only messages whose spam score exceeds our thresh hold  of 6.3. It will function only when the X-Spam-Flag header has a value of YES. Before you construct a spam filter, be sure to set up a spam folder in your email client so that you can retrieve any legitimate messages caught by the filter.

To construct a spam filter based on the X-Spam-Flag header:

1. Open Outlook.
2. From the Tools menu, select Rules Wizard.
3. Choose New.
4. Select the Start from a blank rule radio button.
5. Select Check messages when they arrive.
6. Choose Next.
7. From the list of conditions, select with specific words in the message header.
8. Under Rule description, select specific words.
9. Type: X-Spam-Flag: YES
10. Select Add then Choose OK.
11. Select Next.
12. Select move it to the specified folder.
13. Under Rule description, select specified.
14. Select your spam folder.
15. Choose OK.
16. Choose Finish.
17. Select OK.

X-Spam-Level filter
An X-Spam-Level filter can be used to catch messages whose spam score is less than our thresh hold of 6.3. You might want to create one if you feel that this is too high (doesn't catch enough spam). Before you construct a spam filter, be sure to set up a spam folder in your email client so that you can retrieve any legitimate messages caught by the filter.

WARNING: Be very careful if you create an X-Spam-Level filter. The lower the spam level you choose for filtering, the more likely you will mistakenly catch legitimate mail and send it to your spam folder.

To construct a spam filter based on the X-Spam-Level header:

1. Open Outlook.
2. From the Tools menu, select Rules Wizard.
3. Select New.
4. Select the Start from a blank rule radio button.
5. Select Check messages when they arrive.
6. Choose Next.
7. From the list of conditions, select with specific words in the message header.
8. Under Rule description, choose specific words.
9. Type in X-Spam-Level: followed by your chosen spam level represented by *'s.
   For example, for 60%, you would type 6 *'s : X-Spam-Level: ******
10. Select Add then Select OK.
11. Choose Next.
12. Select move it to the specified folder.
13. Under Rule description, select specified.
14. Select your spam folder.
15. Select OK.
16. Select Finish.
17. Select OK.

More Information
SpamAssassin is a mail filter to identify spam. It is an intelligent email filter which uses a diverse range of tests to identify unsolicited bulk email, more commonly known as Spam. These tests are applied to email headers and content to classify email using advanced statistical methods. SpamAssassin uses a wide variety of local and network tests to identify spam signatures. This makes it harder for spammers to identify one aspect which they can craft their messages to work around.

Reverse DNS Blacklisting tests each incoming email into our systems against a number of online DNS Blacklists and Open Relay Databases such as ORDB, SpamCop & Spamhaus. If a known spam email sender is identified the email is marked as spam before reaching your inbox.

DNS blacklists are lists of IP addresses that are not allowed to connect to your email server. These lists are formed in various ways. Some lists are simple listings by country, some list known spammers and some are reactive and add entries only after an IP address was responsible for sending out junk email.

Open Relay Databases are lists of email servers which allow any connection to relay mail. An open mail relay occurs when a mail server processes a mail message where neither the sender nor the recipient is a local user. In this example, both the sender and the recipient are outside the local domain (or rather, the local IP range, for the technically inclined). The mail server is an entirely unrelated third party to this transaction. The message really has no business passing through this server.

We hope you will benefit from this free service and we will of course be looking further into any additional services which will minimize spam.