Introduction to Email Deliverability

What SaaS teams need to know about email deliverability

Delivering email to the inbox seems straightforward, but it’s actually a surprisingly complex challenge with serious consequences for SaaS apps. Even measuring it is more complicated than you might think. In this article, you will learn:

How email deliverability affects SaaS products

Email plays a critical role in acquiring and retaining customers. For SaaS products and other apps, it’s important to understand that “email” means much more than email marketing. Email notifications such as welcome messages, onboarding prompts, and even utilitarian password resets all are key drivers of user engagement.

Conversely, undelivered email notifications can damage the customer experience. Customers churn when emails sent from your app are lost in spam folders or delayed.

It’s easy to assume your app’s emails are working fine, but delivering email is a surprisingly complex challenge. Simply sending emails isn’t enough—ensuring your users can see and interact with them is critical to your app’s performance and growth.

Product Emails in the User Lifecycle

Unfortunately, many product teams have little visibility into how their email notifications are performing. The first step in understanding and measuring the performance of your app’s email is understanding how many even arrive. Email professionals have a term for that metric: “email deliverability”

Why delivering SaaS email is challenging

In its basic form, email seems so simple; sending an email message to your user takes nothing more than pushing “send” (or making the equivalent call in the programming language of your choice). For SaaS email notifications, your team’s developer might assemble a few lines of a message in their code, add a subject line and a sender address, and call the send function. The message shows up in their inbox when they test it, it looks like what they assembled, and they move on to the next part of their code.

The difficult challenges come when things start to scale. What the developer didn’t realize is that while mail delivery is a trivial task when sending one message here or there, the Internet service providers (ISPs) who host most consumer mailboxes—services such as Gmail, Microsoft, and AOL—become much more picky when you send thousands of messages at a time. In order to protect their customers from spam, they’ll often divert unusual, high-volume bursts of traffic from the inbox to the spam folder.

So consider what happens when a SaaS product begins to grow. The volume of email notifications suddenly increases, and ISPs react by slowing or even blocking delivery of the new messages. When those key alerts such as welcome emails or account verifications never arrive in the inbox, the user experience suffers and introduces roadblocks to continued growth.

This cycle is one reason why industry analysts at 250ok report that 28% of emails end up in the spam folder (or go missing entirely). These missing messages result in lost user disengagement and increased customer churn.

Compare that to the fact that SaaS product teams and other customers who use SparkPost’s email delivery service for notifications and similar emails actually see 96% of their email delivered to their users’ inboxes. How does your own app’s email deliverability compare? Here’s how to measure it.

How to measure email deliverability

Simply put, your deliverability rate is the percentage of your app’s email notifications and other messages that arrive in your users’ inboxes. It’s an essential metric for any email sender, including SaaS teams, because there’s no chance for a user to open, read, and respond if the email never arrives.

Inbox placement is what we really care about, for the simple reason that that’s overwhelmingly the most likely place a recipient is actually going to read our email.

Measuring deliverability seems straightforward. If I send 1000 emails, and my server’s log files say 900 of those arrived at a receiving system like Gmail or Hotmail, then my deliverability is 90%. Simple, right? Not quite. What this figure represents is really the message acceptance rate. That’s because all your email server knows is that the receiving system took the message, but not what was done with it. Did it go to the inbox? The spam folder? The sender really doesn’t know, because in both cases, the SMTP transaction is logged as as successful “250 OK”—SMTP itself doesn’t differentiate spam from good email.

Acceptance rates are the most blunt measure of how systems are technically working, but they don’t say much of anything about the performance of your notifications per se. That’s why simple measures of message acceptance are just a starting point. Inbox placement is what we really care about, for the simple reason that that’s overwhelmingly the most likely place a recipient is actually going to read our email.

UP NEXT: Introduction to Email Authentication and Security

Email authentication is a technical solution to preventing phishing and forged email. That’s essential for every SaaS product. Here’s what you need to know.

More Essential Email Resources

Develop your email industry expertise and master best practices with SparkPost’s email resources.

Email Tools for Developers

These free tools from the email experts at SparkPost make it easy to build and check your app’s emails.

read more

The Big Rewards of Email Deliverability

Learn how third-party data shows the deliverability difference between SparkPost and also-ran cloud service providers yields hard, bottom-line benefits.

read more

Inside the Email Deliverability Lab

This practical course is a great way to get started understanding email deliverability and how to measure email performance.

read more