Why List Quality and IP Reputation Are Crucial in Email Delivery

Effective delivery of emails for marketing, ecommerce or other business functions is essential for a company to build and sustain relationships online.

Of course, the undeniable ubiquity of email has created a myriad of difficulties when it comes to reaching recipients' inboxes. Even if messages are fully legitimate and CAN-SPAM compliant, they can still trigger spam filters used by major ISPs.

One of the primary factors in the success of any email marketing campaign is the quality of the address list. This is a strategic investment that must be protected from abuse and nurtured to achieve maximum value through high-percentage deliverability.

True opt-in, with addresses provided directly to the sender, is the minimum baseline—but it is not a guarantee of success.

Often, the addresses were collected over years, perhaps entered manually by fumble-fingered sales reps. So, it is important to first remove malformed addresses. Age of the list is also a factor, since job changes or simple abandonment of an older email account can lead to a high bounce rate. The ISPs will take action if the bounce rate exceeds 5%, and that's an all too easy threshold to reach.

Age also increases the spam complaint rate. Customers may forget having done business with the company tied to the sending domain, and the knee-jerk reaction for many recipients who don't recognize a sender is to simply hit the spam button.

In addition, another very important factor is IP reputation management. ISP tolerance for spam complaints has become very tight, with 0.1% acceptability for messages through a given IP address that result in a spam complaint by the intended recipient.

In the world of email delivery, senders are identified on the Internet by the IP address of their email server. The reputation of that address is among the most influential variables to delivery success or failure.

Similar to a company's "brand," sender reputation needs to be carefully established and maintained over time. Consider removing addresses that have not been contacted in more than a year from your file. Once the reputation of the sending IP has been established, older addresses can slowly be added to subsequent campaigns, as long the bounce and complaint rates are watched closely.

In layman's terms, the reputation of a company's sending server is similar to an individual's credit score. If it becomes blemished, the chances of email reaching the recipient inboxes are extremely poor. What makes it more challenging is the fickle and unpredictable process in which different ISPs have different methodologies that are dynamic and unpublished, or when recipients who previously opted-in have since changed their mind and labeled the email as spam.

The IP address that each marketer will utilize as a "source" sender address must have an unblemished reputation online and should not be on any ISP blacklists. Increasingly, the ISPs are also looking at the IP reputation of the sending domain as well, so that too should be assessed before the start of any campaign. Sending from the same domain where the addresses were submitted is important, so if the need arises to use an alternate domain as a result of reputation issues, it should match the original domain as closely as possible.

The surest way for an email address to find its way on to an ISP blacklist is to build a track record of recipient complaints or to generate emails that are identified as spam.
 
Anything that adds credibility to the IP address — such as previously using the same IP address to successfully send a high volume of emails (upwards of 100,000) — will help guarantee effective delivery. However, if you suddenly send one million emails from that same IP address, that distribution will most likely fail, as its online reputation has not yet been established for the higher volume of one million.

To truly ensure successful delivery, there must be an environment for working harmoniously with ISPs to ensure their respective users are not plagued with useless, unwanted mail. Also, senders must be able to have their messages reach the inbox while maintaining a clean spam record and an established Internet reputation.

In a world where consumers are bombarded with electronic messages from every touchpoint of their lives, marketers cannot afford to ignore these necessary realities for effective email delivery.

Ron MacDonald is director of sales at SMTP.