Bronto Blog

This is the first in a series of three posts written by our partners at Return Path on issues affecting email deliverability. Want more deliverability information? You can check out their blog, the Email Marketing Water Cooler and sign up for real-time alerts when new content is published.

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JupiterResearch recently released a report on email service providers that found that marketers are focused on deliverability when choosing a vendor. While it’s important to work with a top-quality vendor that has the infrastructure in place to get email through to the inbox, most of the reason your email gets blocked is based on reputation factors that are completely outside the control of ESPs.

There are 5 factors that make up your sender reputation:

1. Complaints: Your complaint rate is the most important element of your sending reputation. ISPs collect complaints in a number of ways, the most well known is the "this is spam" button. But email recipients can also complain by writing to their ISP directly (e.g., abuse@yahoo.com) or by using a third-party service like SpamCop.
2. Unknown User Rate: Sending large volumes of undeliverable email into a system suggests that you might be "guessing" at email addresses in an attempt to spam or that you have poor list management practices. Either way it's a red flag to ISPs.
3. Spam Traps: Receivers use email addresses that have never been used for anything to monitor marketers sending unsolicited messages. They sometimes also use dormant addresses, which may have signed up for email before, for the same purpose. Sending email to a large number of spam trap addresses will label you a spammer.
4. Infrastructure and sending consistency: There are specific ways that ISPs like to see a mailing system set up in order to have some confidence that the email is legitimate. Infrastructure problems aren't common, especially when you use a top-notch ESP like Bronto. Sending consistency means using the same IP address over time. Spammers frequently change IPs to avoid filtering, so ISPs look at brand-new IPs as suspect.
5. Content: Because content filtering was so popular in the early days of spam blocking, its role in filtering decisions is frequently overstated. Return Path research shows that content is a factor in just 17% of blocking decisions. Each ISP uses different criteria in blocking - some pay more attention to content than others. But the shift away from content as a factor is happening rapidly as receivers recognize that the other elements listed here are far easier to monitor - and far harder for spammers to fake.

It sounds overly simplistic, but the key to getting (and keeping) a good sender reputation is to send good email to recipients who have proactively requested it. Of course, the devil is in the details. What is good email? What level of permission is needed for your business? How long can you reasonably consider that permission valid? These are questions that you need to answer in light of your program goals and your subscribers to optimize your email results.

The Next Blog Post in this Series: To Get Delivered You Need to Get Relevant.
Final Post in this Series: Image Suppression: How it Hurts Your Efforts and Depresses Your Deliverability

George Bilbrey, GM & VP of Sender Score, Return Path