Inboxes - Temp Mail Lab API

POST /v1/emails reserves one receiving address for 30 days. If you send an empty JSON object, the API chooses both the local part and domain.

curl --fail-with-body \
  --request POST \
  --header "Authorization: Bearer YOUR_API_KEY" \
  --header "Content-Type: application/json" \
  --header "Idempotency-Key: YOUR_UNIQUE_KEY_16_CHARS_OR_MORE" \
  --data '{}' \
  https://api.tempmaillab.com/v1/emails

Custom addresses

List the domains available to your account:

curl --fail-with-body \
  --header "Authorization: Bearer YOUR_API_KEY" \
  https://api.tempmaillab.com/v1/domains

Then pass local_part, domain, or both when creating the inbox:

{
  "local_part": "signup-check-42",
  "domain": "mail.example.com"
}

Local parts are lowercase, up to 64 characters, and may contain letters, numbers, dots, underscores, and hyphens. Use a domain returned by /v1/domains with creation and receiving enabled.

Idempotency and lifetime

Idempotency-Key is required. Repeating the same key and body returns the original inbox; using the same key with a different body returns 409. Use the returned eml_* ID in API paths. The address receives until expires_at and is never allocated again after expiry.

Last modified on August 15, 2026