How we check each 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.

• Does it look right? — We catch broken formatting and suggest fixes for common domain typos.
• Is it a throwaway address? — We flag known temporary email services that are built to disappear.
• Is it a shared inbox? — We spot addresses like info@ and support@ so you can decide whether they belong in your campaign.
• Can the domain receive mail? — We check that the part after the @ has a working mail server.
• Any domain warning signs? — When available, we check live warning lists for domains linked to abuse or only recently seen.
• Will the server accept it? — We ask the receiving server about the address without sending an email.
• Does the server accept everything? — We try a made-up address to spot catch-all domains where every mailbox appears valid.
• What should you do? — We combine the results into a clear label, score, and plain-English reason.

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