Syntax, mail server, disposable-domain, and role-address checks — all four run in your browser. Nothing you type is ever sent anywhere.
This tool confirms the address is correctly formatted, that its domain has a mail server configured to receive email, and flags disposable or role-based addresses. What it can't do — no browser-based tool can — is confirm the specific mailbox actually exists. That requires a live SMTP conversation with the receiving mail server, which only a backend server can perform. Any tool claiming to do full mailbox verification for free, in your browser, isn't telling you the whole story.
No. It confirms the address is correctly formatted and that the domain can receive mail. Confirming a specific mailbox exists requires a live server-side check that a browser can't perform.
No. Every check — syntax, MX lookup, disposable and role detection — runs entirely in your browser. The only outside request is a standard DNS lookup to confirm the domain's mail server, sent directly to a public DNS resolver.
A temporary address from a service designed to be thrown away after use — useful for avoiding spam signups, but a sign of a low-quality lead if it shows up on a contact list.
An address tied to a function rather than a person — info@, support@, sales@ — often shared by multiple people or unmonitored, which makes it a weaker contact than a named individual.
No. Since everything runs locally in your browser, there's no server-side quota — check as many as you like.