Spam and Filters - Improving the Deliverability of Your Firm's Email Communications By: Joshua Fruchter, President, eLawMarketing (josh@elawmarketing.com)

Introduction – The Rise of Spam and Filters

Over the past several years, HTML email has developed into a popular marketing and business development tool. Trackable, customizable and interactive, HTML email delivers what marketers crave – a targeted audience, instant feedback and measurable results.  After seeing the success achieved by online merchants such as Amazon with HTML email campaigns, professional service firms have increasingly used the medium for their own client communication needs. The result is an abundance of professional service firm email newsletters, alerts, updates and invitations.  

Unfortunately, the low cost of sending millions of email messages encouraged spammers to hijack email technology for their own illegitimate purposes. When the volume of spam became a deluge, Internet Service Providers (“ISP’s”), corporations and consumers fought back by installing filters designed to block spam from their email boxes. The federal government also responded with the CAN-SPAM Act of 2003, which imposes new requirements on email publishers and bans various techniques typically used by spammers. 

The increasing use of filters by ISP’s and corporations to block spam has had one downside for professional service firms engaged in legitimate email marketing – an increased risk that their emails will be improperly labeled as spam and either blocked entirely or routed to users’ junk (bulk mail) folders. The stories range from the comical (a law firm involved in “Viagra” litigation that couldn’t get its emails delivered to a client) to the grave (a sales rep whose response to a prospect’s inquiry was never delivered and who thereby lost the account to a competitor). 

The possibility of emails getting hit with “false positives” has increased interest in deliverability - that is, solutions designed to maximize the delivery of email campaigns to intended recipients without getting blocked.  This article will address key deliverability solutions. First, we will identify the various types of filters employed by ISP’s and corporations, and then describe the solutions available to address each one.

Filter Type 1: Content Filtering

Content filtering is used by anti-spam software systems such as Spam Assassin and SpamKiller.  These systems determine whether to block an email by testing the email’s headers, subject line and body against a database of words, phrases and formatting techniques commonly used by spammers. Each time a certain word, phrase or formatting technique is detected, points are assigned. Emails whose “points” exceed a certain pre-determined score are blocked.

Content filters focus on promotional phrases such as “free,” "work from home", "guaranteed income", or even innocuous phrases such as "click here.” They also assign points to HTML and text formatting such as the use of ALL CAPITAL LETTERS, excessive use of bright colors, or very large fonts.  An email that “brags” about  complying with anti-spam legislation also raises a red flag. The sum of these text and formatting “triggers” comprise a database that can be used by mail servers to detect spam. 

Solutions to Content Filtering

It’s important to remember that just because your email contains a “trigger” word or certain formatting does NOT mean that it will be blocked. It is the aggregation of multiple “triggers” that exceeds the permissible number of points that will cause blocking to occur. As such, one solution to content filtering is employing an email service that, prior to distribution, automatically runs a check of your email subject line and body against the same dictionary used by ISP’s and corporations to block spam, alerts you to any problematic text or formatting that is likely to trigger filters, and then recommends a resolution to each identified problem before the email is sent. For example, the loyalty program vendor MyPoints.com runs all of its subject lines and email content through a copy of Spam Assassin’s filter.

Filter Type 2: List Quality Filtering

Many spam lists contain a large number of bogus addresses and therefore spammers "bounce" a lot of mails with ISP's. To combat this problem, many ISP's have added list quality filters to detect when a large percentage of email addresses are bogus. If the volume of bounces exceeds a certain quantity, all other emails from that source may be disallowed.

Solutions to List Quality Filtering

Any solution that cuts down on the number of “bounces” experienced as a result of invalid addresses will improve the quality of your list and thereby increase the deliverability of emails to valid addresses.

Some email marketing providers will scan your email addresses as they are uploaded to the distribution database checking for known unsolicited addresses, and addresses that don't belong to an individual, such as info@, postmaster@ or abuse@. If these are found, they will not be uploaded.

Other providers stop sending emails to addresses that “hard bounce” either once or after a pre-determined number of campaigns. Suppressing “hard bounces” helps maintain a quality list and avoid the wrath of ISP’s. For those unfamiliar with the jargon, a “hard bounce” is an email address that is undeliverable for reasons that are likely permanent such as “address invalid” or “domain not found.”  In contrast, a “soft bounce” is typically undeliverable for a temporary reason, e.g., “mail server down” or “out of office.”  Providers distinguish between “hard” and “soft” bounces with software that reads the explanation delivered by the receiving mail server to the sending mail server after the former is unable to deliver the message.

Filter Type 3: Volume Filtering

Since many spammers send bulk emails without regard to their accuracy or volume, many ISP's also use volume based filtering. Volume filters focus on the number of simultaneous connections that are opened at any one time with an ISP.

Solutions to Volume Filtering

To avoid triggering volume filters, some providers will monitor the number of connections opened (known as threads) for each ISP domain at any one time. This ensures emails are delivered at a maximum rate without triggering volume filters at large ISP's such as AOL or Yahoo.

Other vendors will stagger delivery of emails to avoid volume triggers.  The distribution will take longer but the delivery rate will be higher.

Filter Type 4: IP Address Filtering

Blacklists

Each mail server distributing email has a unique IP address. Many organizations have employed IP address filtering as a means to identify IP addresses that send spam, and to disallow all emails from these IP addresses in their system. The technique of adding suspected IP addresses to a filtering list is called "blacklisting." There are numerous active blacklists in use today; some maintained by private companies and individuals, and some operated by anti-spam organizations. A growing number of organizations are filtering incoming mail this way.

Whitelists

A related concept, where a list of "trusted senders" is used to determine which email is legitimate, is called "whitelisting." White lists are lists of IP addresses of organizations that are trusted to deliver only legitimate messages.

Typically an ISP will have several guidelines that a sender will need to follow to qualify for the white list status, including email formatting, name capture tactics, and client enforcement. White lists have been developed and adopted by a growing number of organizations as part of their spam defense systems.

Solutions to IP Filtering

Whitelisting

To avoid IP filtering it is recommended that firms use a vendor that has developed “whitelist” relationships with key ISP's, anti-spam organizations, and others. Such relationships dramatically increase the likelihood that your emails sent via the vendor’s system will reach the intended audience. 

For example, some vendors participate in a program devised by AOL that automatically unsubscribes email recipients from a vendor’s system after those recipients click the spam reporting button in AOL.  Because the automatic unsubscribe action reduces the potential for abuse, this solution allows AOL to continue letting emails sent by the vendor’s servers to reach AOL customers even where individual emails have been reported as spam.  Other ISP’s will provide vendors with lists of email subscribers that have reported email from a vendor as spam so that these subscribers can be removed from the vendor’s system.

IronPort BondedSender^TM  

The 800-pound gorilla in the whitelisting space is Iron Port, which maintains a  database of IP addresses, domains and subdomains called BondedSender that is currently whitelisted with over 28,000 receiving domains, organizations and ISPs.

BondedSender provides a "stamp of approval" to senders who pass a screening and certification process, pay an application fee, and post a bond against which a small sum is deducted for every spam complaint received (though Iron Port claims to weed out false positives).

The big news is Microsoft's recent agreement to pass users of IronPort's Bonded Sender program through its spam filters. Thus, for example, when your email hits a Hotmail server, the filter will query the Bonded Sender database. If your information comes up, you zip right through the spam-filter thicket. Since the same set of filters and rules used with Hotmail and MSN are also used in Outlook and Exchange, Microsoft’s adoption of BondedSender is significant not just to B2C merchants but also to B2B companies such as professional service firms sending emails to corporate domains.

Emailers can sign up for BondedSender directly with Iron Port or through a participating email marketing software vendor that will manage the application process and post the bond (though they’ll still make you pay the penalty for each spam complaint).

Private IP Address

A premium option offered by some vendors to protect against IP Filtering is a unique IP address for individual clients – that is, an IP address used only by that client to send email and not shared by any other client. The unique IP address will be registered within the vendor’s “whitelist” database to ensure recognition by major ISP's with whom the vendor has relationships. Because no other client will be using this IP address to send email, the user of the unique IP address is not exposed to any risks that may be posed by the email marketing practices of other organizations.

Monitoring

A Private IP address is often coupled with monthly monitoring of such addresses by an abuse desk. Such monitoring might include regular reviews of SMTP delivery logs to detect any potential "false-positive" spam filtering or blocking before it affects deliverability, and attempted removal of any filtering or blocking that may be put in place at a specific recipient. Removal of blocking often means contacting the mail administrator at a specific recipient or at an ISP to try and resolve the issues causing the blocking. By outsourcing monitoring and resolution to a dedicated third party, a firm avoids the time and expense of having someone in-house handle email delivery issues and ISP relations.

Conclusion

The bottom line is that email remains a viable and successful channel for reinforcing the expertise of a professional service firm, communicating important developments and news to clients, and identifying client interests, concerns and needs. However, to achieve these benefits, a firm’s email must avoid filters and get delivered to the inboxes of the intended recipients. If you suspect your emails are getting filtered, it may be time to consider some of the deliverability solutions described in this article.

Joshua Fruchter, Esq., is the president and co-founder of eLawMarketing, which handles email newsletter design and distribution for the Atlanta Chapter of the ALA and over 40 other law firms and legal organizations. The firm also provides website development and search engine marketing services. Joshua can be contacted at 866-833-6245 or by email at josh@elawmarketing.com. The firm's website is at http://www.elawmarketing.com.

This article originally appeared in the September 2004 issue of PM Forum Magazine and is being reprinted with the permission of the North American Region of PM Forum, a global organization of over 3,000 professional service marketers.

Editor: Debra F. Goldman (dgoldman@gmlj.com) (This publication is the property of the Atlanta Association of Legal Administrators. Reproduction or reprint without prior permission is strictly prohibited. Click here to request reprint permission.)

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