Contents

• Introduction
• System-Wide Measures
• Web-Site Protection Measures
• Individual User Options

Introduction

Summersault has a number of mechanisms in place to reduce the amount of unwanted bulk e-mail that enters our network. Please note that Summersault's Acceptable Use Policy strictly prohibits the use of any of our resources for sending or facilitating unsolicited bulk e-mail.

You can read all about the spam problem and various ways to fight it at http://spam.abuse.net/. Managers, system administrators and persons generally interested in anti-spam techniques may also benefit from reading an Anti-Spam HOWTO written by Summersault's Chris Hardie and maintained for the qmail (mail server software) community.

The measures described below apply to Summersault hosting customers who retrieve mail directly from our primary mail servers via the POP or IMAP protocols. If your mail is forwarded to a third party account, or if you have some other non-standard setup on our system or otherwise, you should contact us for more information.

Also note that, given the constantly changing nature of the spam problem, we may update the measures we use to filter and block bulk e-mail at any time. We will always try to balance our users` need for legitimate mail to get through against the need to block junk mail, but we encourage you to be aware of the measures in place by checking back to this page and/or contacting a Summersault representative.

We value your feedback on this serious issue - please contact us if you have any questions or suggestions for how we can better help to address it.

System-Wide Measures describe actions/rules applied to ALL mail entering Summersault's network. The current system-level measures in place include:

• All e-mail delivered to our mail servers must either originate from or be destined to an e-mail address in a domain hosted by Summersault (i.e. no open relaying)
• All e-mail delivered must have a valid domain name in the envelope sender address
• All e-mail delivered must conform to widely accepted mail standards and protocols.
• E-mail is blocked from hosts or senders that have a proven record of only sending junk mail.
• E-mail is blocked from computers and servers that are classified as "open relays" or spam-friendly by the following third party blocking list services:
  • zen.spamhaus.org
  • bl.spamcop.net
  • dnsbl.njabl.org
• Mail containing known viruses or worms are not allowed to go through to the recipient
• Mail is scanned by SpamAssassin to determine its "spam score" (see Individual User Mail Filtering below). Mail with a very high spam score is rejected.

Our webserver can be configured to send spambots to an invalid page to prevent them from stealing email addresses from websites hosted on our server. This can be useful if you post your e-mail address on your website, but don't want known spambots to pick up on it and start sending junk mail to it. This measure can help, but doesn't guarantee that your address will be picked up from your website. If you would like this feature enabled for your domain, contact us by submitting a support request.

Each message that enters the Summersault mail system is scanned by a program called SpamAssassin, which runs tests on the content of the message. The scanning does not affect the content of your message, but it does add its findings into the headers of the message, and ads the text "*****SPAM*****" at the beginning of the Subject line. In particular, messages that it thinks are spam will get an "X-Spam-Flag: YES" header:

From: raubenheimer5rr76@excite.com
Subject: *****SPAM***** MAKE MONEY FAST!!!!
Date: Fri, 07 Dec 2001 00:03:25 -0500
X-Spam-Flag: YES

Note that you might have tell your mail reading program to "view full headers" in order to see these. (SpamAssassin adds other header information that shows how it determined that the message was or wasn't spam, which may be interesting to review.)

If you so choose, you can tell a mail client that supports filtering (most common ones, like Outlook, Eudora, and Netscape, do) to filter messages containing this "X-Spam-Flag" header. NOTE that if you tell your mail client to delete messages containing these headers, you may indeed lose legitimate e-mail; we recommend that you maybe filter the messages to a "junkmail" folder that you check periodically, and then purge.

Note that you should refer to your software vendor's documentation for details on how to configure filtering -- Summersault cannot provide technical support in this area.

In the future, Summersault may provide features that allow users to customize the way SpamAssassin determines spam scores for the messages coming in to their mailboxes.

Also, note that you should avoid setting up a "catch-all" account for your domain, as this will increase the amount of spam that you receive; many spammers will send mail to randomly selected addresses at a given domain. By setting the "catch-all" to "bounce" (which is the default setting for new accounts), you can avoid this problem.