The checks we run on every address

Each address goes through a series of checks. If an early check finds a clear problem, we stop there and mark the address — no need to keep going. Here is what we look at, in plain language.

• Spelling and shape — is it a properly formed email address? This catches typos like "gmial.com" or "yhaoo.com".
• Throwaway check — is it a temporary, burner address designed to disappear?
• Role check — is it a shared inbox like info@ or support@, rather than a person?
• Domain check — does the part after the @ actually exist and accept mail?
• Reputation check — is the domain flagged as a known source of spam or abuse?
• Mailbox check — does this exact mailbox exist? We ask the receiving server quietly, the way a mail server would, without ever sending a real message.
• Catch-all check — does the domain say yes to every address, real or not?
• Confidence score — we combine everything above into a single score from 0 to 100.

Each address in your results shows which checks raised a flag, so you can always see the reasoning behind its label.