Free Email Validator

Every email you send to a bad address chips away at your sender reputation. Hit a 2% bounce rate and providers like Gmail start throttling your campaigns. Hit 5% and you're looking at the spam folder. Our email validator catches invalid addresses before they do damage, checking syntax, domain DNS, MX records, and known disposable email providers in one pass.

How email validation actually works

Validation happens in three layers. First, we check the format — does the address follow RFC 5322 rules? Things like missing @ signs, double dots, or spaces fail here. Second, we query the domain's DNS to confirm it exists and has MX records pointing to a real mail server. Third, we cross-reference the domain against a database of 30,000+ known disposable and temporary email providers. Each layer catches a different class of bad address, and together they filter out the vast majority of undeliverable emails.

Why this matters for email marketers

ISPs track your bounce rate on a rolling basis. Mailbox providers like Gmail and Microsoft use it as a core signal when deciding whether to deliver your emails to the inbox or the spam folder. Studies show that senders with bounce rates under 1% see 15-20% better inbox placement than those hovering around 3-4%. If you're running paid acquisition and collecting emails through forms, validation is the single highest-ROI step you can take before sending your first campaign.

Common mistakes to avoid

The biggest mistake is only validating emails at the point of collection and never again. Email addresses go stale — people leave jobs, abandon accounts, and domains expire. You should re-validate your list every 3-6 months at minimum. Another common error is trusting a "valid syntax" result as proof of deliverability. An address can be perfectly formatted and still bounce because the mailbox doesn't exist. Finally, don't skip validation on small lists. Even a list of 500 subscribers with 10 bad addresses gives you a 2% bounce rate, which is enough to trigger deliverability problems.

How to use this with your email workflow

Start by validating new addresses at signup. Then, run your existing list through validation quarterly. Pair this tool with our bounce rate calculator to track your list health over time. If you find a high percentage of disposable addresses, tighten your signup forms — consider adding a confirmation step. For domains you're unsure about, run a quick domain reputation check to see if the sending domain itself has issues. And always check your deliverability score after cleaning your list to measure the impact.