Benjamin Franklin certainly wasn’t talking about email deliverability when he said, “It takes many good deeds to build a good reputation, and only one bad one to lose it,” however this quote could easily apply to the factors impacting ISPs’ email filtering decisions.
A recent Return Path study confirms that a marketer’s sender reputation is the key to achieving high inbox placement rates and avoiding the spam folder. Return Path’s Analytics Team reviewed data on more than 18 million IP addresses, collected from 30 of the world’s top ISPs and other large-volume mail receivers. These ISPs represent mailboxes in North America, South America, Europe and Asia.
In total, there are three major categories of filtering decisions:
- Reputation: A quantitative measurement of the desirability of email based on the reputation of the sending server’s IP address. This is affected by a variety of weighted factors, however complaints and list hygiene (i.e., unknown users, spam traps) have the greatest impact.
- Infrastructure: How your mail server is configured, including the use of authentication protocols like reverse DNS, SPF, SenderID and DKIM. Having a good infrastructure lets the ISPs know you are making an effort to follow their protocols, while failing to have these basics in place makes you look unsophisticated at best and possibly malicious at worst.
- Content: Filtering based on content has gone way beyond the days when words like “free,” “discount” and “save” triggered spam filters. Today, ISPs apply these filters later on in the process and only on messages coming from IPs where the reputation or infrastructure signals are unclear. In addition, they now search out features of the message that correlate with complaints, spam trap hits and other “negative” signals.
Having good sending practices is the key to building and maintaining a reputable sender reputation score. The higher your score, the more likely it is that your email will reach the inbox.
As the chart below shows, IPs with low Sender Scores (below 60) are rejected at the gateway at an extraordinarily high rate. In the mid-range (60-79), the amount of rejected email goes down slightly, but the amount of email filtered goes up. It is only at the very highest levels (80-100) that email is routinely “accepted” into the ISP system. In fact, IPs with a Sender Score of 100 are 38% more likely to get into the inbox than those with a Sender Score of 50.
Establishing a good Sender Score, maintaining it and monitoring any fluctuations to it are integral to the health of your email program. After all, messages that don’t reach the inbox won’t drive activity, engagement or purchases – essential actions for realizing email ROI.
Your reputation and your Sender Score are well within your control. If Ben Franklin’s quote about reputation were applied to email deliverability, the “good deeds” he refers to are all related to your sending practices. The better your practices, the higher your Sender Score and the more email will reach the inbox. Don’t know your Sender Score? Visit Return Path’s free reputation portal: www.senderscore.org.