{
  "name": "MailSenpai",
  "description": "Public APIs of MailSenpai: free checks for email deliverability (DNS records, blocklists) and the SMTP Senpai transactional email API.",
  "image": "https://en.mailsenpai.com/wp-content/uploads/favicon/favicon-192.png",
  "url": "https://en.mailsenpai.com/apis.json",
  "created": "2026-10-12",
  "modified": "2026-10-12",
  "specificationVersion": "0.19",
  "tags": [
    "email",
    "deliverability",
    "dns",
    "blocklist",
    "smtp",
    "transactional email"
  ],
  "apis": [
    {
      "name": "MailSenpai DNS check API",
      "description": "Free check of the SPF, DKIM, DMARC and MX records of a domain, with what to fix and the values to publish. No key, CORS enabled, 30 checks per hour per IP.",
      "image": "https://en.mailsenpai.com/wp-content/uploads/favicon/favicon-192.png",
      "humanURL": "https://en.mailsenpai.com/dns-check-api/",
      "baseURL": "https://app.mailsenpai.com/tools",
      "tags": [
        "email",
        "dns",
        "spf",
        "dkim",
        "dmarc",
        "mx",
        "free"
      ],
      "properties": [
        {
          "type": "Documentation",
          "url": "https://en.mailsenpai.com/dns-check-api/"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/mailsenpai-dns-check-openapi-1.0.0.yaml",
          "mediaType": "application/yaml"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/mailsenpai-dns-check-openapi-1.0.0.json",
          "mediaType": "application/json"
        }
      ]
    },
    {
      "name": "MailSenpai blacklist check API",
      "description": "Free check of a public IPv4 address or a domain on public email blocklists, list by list, with the official removal pages. No key, CORS enabled, 10 checks per hour per IP.",
      "image": "https://en.mailsenpai.com/wp-content/uploads/favicon/favicon-192.png",
      "humanURL": "https://en.mailsenpai.com/blacklist-check-api/",
      "baseURL": "https://app.mailsenpai.com/tools",
      "tags": [
        "email",
        "blocklist",
        "dnsbl",
        "ip reputation",
        "free"
      ],
      "properties": [
        {
          "type": "Documentation",
          "url": "https://en.mailsenpai.com/blacklist-check-api/"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/mailsenpai-blacklist-check-openapi-1.0.0.yaml",
          "mediaType": "application/yaml"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/mailsenpai-blacklist-check-openapi-1.0.0.json",
          "mediaType": "application/json"
        }
      ]
    },
    {
      "name": "SMTP Senpai API",
      "description": "Transactional email sending, log, suppression list, webhooks and website forms of SMTP Senpai, the MailSenpai SMTP relay. Requires an account key.",
      "image": "https://en.mailsenpai.com/wp-content/uploads/favicon/favicon-192.png",
      "humanURL": "https://en.mailsenpai.com/smtp-api/",
      "baseURL": "https://app.mailsenpai.com/relay/v1",
      "tags": [
        "email",
        "smtp",
        "transactional email",
        "webhooks"
      ],
      "properties": [
        {
          "type": "Documentation",
          "url": "https://en.mailsenpai.com/smtp-api/"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/smtp-senpai-openapi-1.2.0.en.yaml",
          "mediaType": "application/yaml"
        },
        {
          "type": "OpenAPI",
          "url": "https://www.mailsenpai.com/wp-content/uploads/api/smtp-senpai-openapi-1.2.0.en.json",
          "mediaType": "application/json"
        }
      ]
    }
  ],
  "maintainers": [
    {
      "FN": "MailSenpai",
      "url": "https://en.mailsenpai.com/"
    }
  ]
}