Why Validating Email Addresses Matters

We know that a positive reputation with mailbox providers is a basic need for anyone sending valuable, time-sensitive emails. After all, if your email can’t be delivered to the inbox, or delivered at all, then nothing else matters down the chain of engagement and conversion.

The “sender reputation” you earn with an ISP is based on a number of factors, but a very important one is only sending emails to people who actually exist. If you constantly send to non-existent accounts, you’re going to get more than a bounce in return—you’re at dire risk of ruining your reputation. Frequent hard bounces show ISPs that you aren’t using best practices when collecting and maintaining your email lists. It gives them pause about how much they want to accept your mail and what to do with it when or if they accept it.

What best practices do I mean? First and foremost, only sending to users who’ve opted in. That’s a fundamental rule. And ideally, senders will use a two-step opt-in or confirmed opt-in process for any email they send. That means that, after a user has opted in via a web form or similar, sending a single confirmation/verification email to a recipient (and not sending any additional messages) until that person has gone into their inbox and clicked on the email. This verifies their existence and confirms that they really do want to receive your emails.

More senders are adopting this type of two-step opt-in practice, which is great—but even sending just one verification email to an invalid address can negatively impact your reputation. So what should senders do? Wouldn’t it be great to verify that an email address you are sending to is valid before you do a single send?

Introducing Recipient Validation

Well, good news. That’s where SparkPost’s new Recipient Validation comes in. It’s an easy, efficient way to verify that addresses are valid before you send. Recipient Validation leverages SparkPost’s email expertise and industry-leading data footprint (after all, our technology is used to deliver more than 37% of the world’s B2C email!) to help you guard against:

  • Email address syntax errors and typos
  • Invalid domains
  • Throw-away addresses on disposable domains
  • Non-existent mailboxes
  • And other common errors

Today, Recipient Validation can be used in two ways: validation of single addresses via API or UI and interactive validation of longer lists in the SparkPost web app. We anticipate providing additional capabilities in the future.

We are excited to launch Recipient Validation today. (Note: the feature currently is not available on the SparkPost EU product.)

Get Started with Recipient Validation

Calling our Recipient Validation API couldn’t be simpler:

GET /api/v1/recipient-validation/single/some@ddress.com

We’ll return a JSON object indication whether the address was valid or invalid. Any invalid email address responses will also provide a reason why it is invalid.

  "results": {
    "valid": true,
    "is_role": false,
    "is_disposable": false

To validate a list of emails, use the Recipient Validation feature of the SparkPost web app to upload the list. You’ll get a .csv file in return that notes invalid addresses and reasons.

Learn more about using Recipient Validation and API implementation details in our documentation.

Looking Ahead

This release is just the start; we anticipate developing further capabilities in the near future. We’re eager for your feedback on Recipient Validation and how to make it most useful to you.

We are confident it will help you avoid excessive hard bounces to protect your reputation and to get a more accurate view of your email performance.