SimpleVerifier

SimpleVerifier checks each email address the way a mail server would: it connects to the recipient's server, asks whether the mailbox exists, then disconnects before anything is sent. Upload a CSV or check one address, and every row comes back valid, risky or invalid with the reason. Valid means the mail server confirmed the mailbox. Catch-alls, role addresses and providers that hide mailbox status stay risky, never guessed valid.

Pricing is monthly, not credits. Starter is $9 a month for 2,500 checks. Pro is $39 a month with no cap: the first 100,000 checks a month run at full speed, then big lists run in a paced lane, never cut off. Business ($99) and Agency ($249) raise the full-speed volume to 300,000 and 750,000 and add seats. One-time packs start at $15 for 10,000 and never expire. The first 100 checks are free with a Google sign-in, no card.

Pro and up add a REST API and a remote MCP server for AI agents, and it connects to Instantly, Smartlead, HubSpot and Mailchimp by API key, tagging each contact with its result. Phone numbers get a free format and number-type check. Website: simpleverifier.com