How ISPs Think to Determine Email Deliverability
Last Saturday I woke to a glimpse of technology gone wrong– my cat had stepped on my iPhone, summoning Siri. As she meowed, Siri interpreted the cry of my kitty as a request to FaceTime my cousin in Los Angeles– at 4am his time. Siri is a computer program that has been thoughtfully developed, but occasionally makes a mistake. It’s up to me as the user to understand and alter my behavior to best utilize the power of Siri.
Like Siri, Internet Service Providers (ISPs) are programmed by people who write the rules, but it’s the computers who govern them. Meaning, there is very little room for error. When your business sends an email, ISPs determine whether or not to deliver your message to their customers (your recipients). Understanding how this process works can allow you to think strategically when sending, and take steps to improve your deliverability rate.
Here’s how ISPs think to determine email deliverability.
- Language in email body: If the content in your email seems like something people likely wouldn’t want to read (e.g. overly repeated text, spammy language, lots of special characters), they will flag the message and send some of the emails to the spam filter.
- Unsubscribe link: When sending a campaign, you are legally required to allow people to unsubscribe from your list. If you do not include an unsubscribe link, you run the risk of people reporting your email as spam instead of unsubscribing, which is a lot worse. ISPs count spam reports very heavily and will penalize your future campaign sends by assuming your messages will be spam and putting them in the spam filter proactively.
- Image/text ratio: ISPs cannot read the text included within an image. As a result of this, they have to assume that images include text that could be phishing attempts or “bad” content. If your emails are predominantly images, ISPs won’t trust your content and will send more of it to the spam filter. To get around this, include text that describes each of your images to your recipients and, at the very least, include alt-text for each of your images.
- Link domains: Do the destination URLs in your link point to either the domain in your from address or sending domain? If not, ISPs may believe that you are affiliate marketers (getting paid to send emails to your recipients peddling other people’s products), which are generally emails that people do not want to receive. Make sure the domains of the links in your email are consistent – this is proof that you are a legitimate brand and gives ISPs more confidence that you are sending good emails.
Looking for More Information?
Check out these resources on email deliverability: