Fighting Spam

DigitalPath now officially provides anti-spam measures. We use a combination of spamassassin + qmail servers to identify, move and stop spam from hitting your E-mail box. Currently, any X-Spam-Status message with a number greater than 10 will be rejected by the system. If you subscribe to our Spam Filtering service, any message greater than a level 5 will be placed into a Spam folder. This Spam folder can be accessed through the IMAP webmail interface at webmail.digitalpath.net. These messages can be moved or deleted from the Spam folder to your Inbox. If you are using MS Outlook with IMAP, the spam folder will automatically appear in your folders.

Additional User control over Spam Filtering.
It is up to you the customer to either perform your own spam filtering with the assistance of third party software or to configure your own email client to make use of the spam identification tags that we provide as a courtesy.

For more information on spam, please see this Wikipedia article.

Overview

DigitalPath currently makes use of an Internet community-supported SBL/XBL ( Spamhaus) to reject a large amount of "obvious" spammers. Despite this, a lot of spam still gets through. We do not use some of the more aggressive RBL's (such as Spamcop) to avoid unnecessary false positives and blocked legitimate email.

In addition to making use of the RBL, we also use SpamAssassin with a well-trained Spam/Ham corpus additionally backed by DCC and custom rules written by ourselves and contributed from the SARE project to further identify spam. This spam identification has proven to be very accurate, but in the interests of not blocking legitimate customer email we only "mark" these emails as spam and do not actively block them.

Making use of DigitalPath Spam Tagging

If you like, you may configure your mail client to use the spam tags added by our software to help identify and filter messages as you download them to your mail client. We provide instructions for this for two common mail clients and more may be added if demand warrants:

• Outlook
• Thunderbird

As Outlook Express does not support filtering based on envelope headers, it is unable to make use of our spam tags. Please consider moving to a more full-featured email client.

Do it Yourself

For the technically savvy, you can use the X-Spam-Status header (it will be set to Yes if the message is spam) or the X-Spam-Level header which will have a number of asterisks (*) -- the higher the number, the more likely that the message is spam. In general, five asterisks will be the low-end threshhold for a spam message.

Here is an example header from a spam message:

Received: (qmail 11663 invoked by uid 1542); 22 Aug 2006 22:16:24 -0000
Received: by simscan 1.1.0 ppid: 11620, pid: 11621, t: 2.2236s
         scanners: clamav: 0.88.4/m:40/d:1705 spam: 3.1.0
X-Spam-Flag: YES
X-Spam-Checker-Version: SpamAssassin 3.1.4 (2006-07-25) on 
        chico-smtp1.digitalpath.net
X-Spam-Level: ********
X-Spam-Status: Yes, score=8.7 required=5.0 tests=AWL,BAYES_95,DCC_CHECK,
        MSGID_FROM_MTA_HEADER,UNPARSEABLE_RELAY autolearn=no version=3.1.4
X-Spam-Report: 
        *  0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay
        *      lines
        *  3.0 BAYES_95 BODY: Bayesian spam probability is 95 to 99%
        *      [score: 0.9633]
        *  2.8 DCC_CHECK Listed in DCC (http://rhyolite.com/anti-spam/dcc/)
        *  0.0 MSGID_FROM_MTA_HEADER Message-Id was added by a relay
        *  3.0 AWL AWL: From: address is in the auto white-list
From: "Paul Williams" <JameszGcMartin@atkinsonresort.com>
To: xxxxxxxx@digitalpath.net
Subject: Re: hey
  

The spam-specific headers are bolded here.