Verified means a mailbox answered

An email list is only worth sending to if the addresses work. Bad addresses bounce, and bounces damage the reputation of the domain you send from. This page explains where Leadraft's emails come from, how we check them, and exactly what each grade means.

Where do the emails come from?#

From each business's own public website, never from guesswork alone or a purchased list. We read the pages a business uses to be contacted, such as the home page, contact page, footer and sitemap. For sites that only show their content after JavaScript runs, we load them in a real browser. We keep up to five addresses per business, each with its role (for example "sales" or "general") and the page we found it on.

When a website shows no address, we may suggest a likely one from common patterns. These guesses are only offered when the domain has a working mail server, and they're checked like any other address.

How is an email checked?#

Every address goes through the same steps:

1. Syntax and clean-up: malformed addresses are rejected and the rest are normalized.
2. Disposable domains are flagged against a public list of throwaway email providers that's refreshed weekly.
3. Mail servers: we look up the domain's MX records, the servers that accept its mail.
4. Mailbox check: we connect to that server and ask whether it will accept mail for the address (RCPT TO). Then we hang up before any message is sent. No email reaches anyone.
5. Catch-all check: we also ask about a random address that can't exist on the same domain. If the server says yes to that too, it accepts everything, and its yes about the real address proves nothing.

We pace ourselves: one connection per mail server at a time, with pauses between checks.

What do the grades mean?#

What happens when we can't tell?#

Some servers throttle or delay checks, and sometimes our checker is unavailable. A check that fails is never graded invalid. The address waits and is checked again later. We would rather show you fewer verified emails than call a working address dead, or a dead one verified.

What we never do#

• Send an email to check an address.
• Mark an address verified on a mail server lookup alone.
• Call accept-all addresses verified.
• Charge you for addresses that aren't verified.

Limits#

A verified grade means the mailbox accepted mail when we checked it. People leave jobs and mailboxes close, so check again before a big send if the list is old. Some large providers don't answer mailbox checks reliably. Those addresses take longer to grade, and some can't be graded at all.