Quickstart

verify your first email address with the mailfloss api in under five minutes this is the current mailfloss api (v1) the original email verification api ( api mailfloss com/verify?api key=… ) is now deprecated and will sunset on june 1, 2027 build new integrations on v1, and plan to migrate existing ones — see authentication authentication for the api key → bearer change 1\ get your api key your api key lives in the mailfloss dashboard under settings → api it's a secret — treat it like a password, keep it server side, and never embed it in client side code or commit it to source control 2\ verify a single email send your key as a bearer token and call get /v1/verify curl https //api mailfloss com/v1/verify?email=test\@example com \\ h "authorization bearer your api key" a successful call returns the verdict directly as the response body { "email" "test\@example com", "status" "deliverable", "reason" "valid", "passed" true } status — the deliverability verdict for the address reason — the specific signal behind the verdict passed — a convenience boolean for "safe to send " each successful verification consumes one credit from your account see the api reference for the full list of status and reason values 3\ handle errors errors come back in a consistent envelope — branch on the stable code , never on the human readable message { "error" { "code" "insufficient credits", "message" "your account is out of verification credits ", "type" "billing error", "request id" "req a1b2c3" } } full details in the errors guide 4\ verify in bulk for lists, submit a batch job and poll for results \# submit curl x post https //api mailfloss com/v1/batch verify \\ h "authorization bearer your api key" \\ h "content type application/json" \\ d '{ "emails" \["a\@example com", "b\@example com"] }' \# > { "id" "job 123", } \# poll status curl https //api mailfloss com/v1/batch verify/job 123/status \\ h "authorization bearer your api key" \# fetch results (paginated) once status is "completed" curl https //api mailfloss com/v1/batch verify/job 123/results \\ h "authorization bearer your api key" post endpoints accept an optional idempotency key header so a retried submit never double charges see the reference for the batch request shape next steps authentication — bearer vs the legacy api key parameter, and key handling pagination — how list responses page connect an esp — verify first automation across 18 email platforms api reference — every endpoint, parameter, and response shape