Have you ever thought about how and why email gets delivered? Deliverability refers to the likelihood that an email message you send will actually arrive at its intended destination. Emails don’t always make it to the intended recipient’s inbox. They can be delivered to the junk folder (sometimes referred to as the spam folder), rejected by the receiver’s email infrastructure (usually in the form of a bounce), or disappear altogether (for example, when the receiving system drops the message without informing the sender or recipient). Some ISPs have even created default folders based on user engagement to help recipients better organize their messages, and email will be delivered to these folders, rather than the inbox itself.

As an email sender, you want as many messages as possible to be delivered to your recipients’ inboxes. The best way to improve delivery is to send high-quality email; that is, email that recipients find valuable. Email recipients only want your email if they can extract value from the message. That value can come in many forms, such as offers, order confirmations, sweepstakes notifications, or even social network communications. Value, of course, is a loaded word, since different things make email messages valuable to different people.

Email quality equals value to the email recipient. Despite its subjectivity, ISPs try to predict email quality as accurately as possible using a variety of metrics to gauge whether a message is wanted (and thus valuable) or is not wanted (and thus considered spam). These metrics include various internal computations based on anti-spam technology and recipient inputs that ISPs attempt to quantify.

You, as the sender, build trust with a receiver (whomever or whatever is behind the address you’re sending to) by sending high quality email over time. This trust is referred to in the industry as reputation. Receivers use metrics to assess the value of a sender’s email. These metrics are often combined into scores, and are typically referred to as a sender’s reputation.