What is email validation?

You hit send on a campaign to 10,000 addresses. Three days later, you notice 800 bounces. Some of those bounce because the address is fake or inactive. Some bounce because the domain doesn't exist. Some bounce because the mailbox is full or the server's down for the moment. How do you catch these problems before you send?

That's what email validation does. It's a series of checks that run on an email address to predict whether mail sent to it will actually reach a real mailbox. Think of it as a quality test on your list before you use it.

Here's how it works. A validation tool checks the syntax first. Is it actually formatted like an email address? captain@tidalmail.com passes. captain@tidalmail passes not. Then it checks the domain using DNS records to confirm that tidalmail.com is a real, active domain with mail servers running. Finally, it attempts limited SMTP interactions (that's the protocol mail servers speak) to see if the mailbox actually exists and can receive mail.

The tool gives you a result. Valid, invalid, or risky. A valid address has syntax, an active domain, and an accepting mailbox. An invalid address fails one or more checks. A risky address passes most checks but has patterns that suggest it might be a spamtrap or a typo waiting to happen.

You can validate at signup (catch problems as they happen) or in bulk on your existing list (clean what you already have). Either way, validation helps you avoid sending to broken addresses, which tanks your domain reputation and hard bounce rates that mailbox providers watch closely.

Want to see how your list would score? Try our free email header analyzer to check your setup, or start with a free blocklist check to see if your domain's already in trouble. If you're worried about your whole list, we offer done-for-you list cleaning.