Couryo free email tools

Checks one email address without sending anything: format, typo in big providers ("gmail.com.br" → "gmail.com", "hotmial.com"), disposable inbox, shared mailbox (contato@, sales@) and whether the domain receives email (MX). Verdict valid, risky or invalid, with did_you_mean. The mailbox itself is never probed. Free, read only. / Confere um endereço sem enviar nada: formato, erro de digitação, e-mail temporário, caixa compartilhada e se o domínio recebe e-mail.

{
  "type": "object",
  "properties": {
    "email": {
      "type": "string",
      "description": "The address to check"
    }
  },
  "required": [
    "email"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Checks the email setup of any domain: SPF (one record, ending, the 10 DNS lookup limit), DKIM on the common selectors (or dkim_selector), DMARC policy and reports, MX and mailbox provider, MTA-STS, TLS-RPT and BIMI. Answers a 0 to 100 score, a grade, the fix for each problem in plain words and records ready to copy. Free, read only. / Confere SPF, DKIM, DMARC e MX de qualquer domínio, com nota e a correção de cada problema.

{
  "type": "object",
  "properties": {
    "domain": {
      "type": "string",
      "description": "e.g. \"example.com\" (a URL or an address also works)"
    },
    "dkim_selector": {
      "description": "A DKIM selector to look up besides the common ones (the s= of the DKIM-Signature header)",
      "type": "string"
    }
  },
  "required": [
    "domain"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Explains a bounce or SMTP error text ("550 5.7.515 Access denied", "452 4.2.2 mailbox full") in plain words: hard (the address does not work), soft (temporary) or policy (a provider rule, not the address), the provider and the next step. Free, read only. / Explica uma devolução ou erro SMTP em linguagem simples, com o próximo passo.

{
  "type": "object",
  "properties": {
    "message": {
      "type": "string",
      "maxLength": 4000,
      "description": "The error or bounce text, as it came"
    }
  },
  "required": [
    "message"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Builds one SPF record (TXT at the domain) from the services that send for it: includes, IPv4 and IPv6, mx and a. Starts with ~all (softfail), the safe choice; use policy fail (-all) once every sender is listed. Remember the limit of 10 DNS lookups (each include costs at least one). Free, no network. / Monta o registro SPF a partir dos serviços que enviam pelo domínio.

{
  "type": "object",
  "properties": {
    "includes": {
      "description": "include: hosts, e.g. [\"_spf.google.com\"]",
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "ip4": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "ip6": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "mx": {
      "description": "Servers in the domain's MX may send",
      "type": "boolean"
    },
    "a": {
      "description": "The domain's own address may send",
      "type": "boolean"
    },
    "policy": {
      "type": "string",
      "enum": [
        "softfail",
        "fail",
        "neutral"
      ]
    }
  },
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Builds one DMARC record (TXT at _dmarc.<domain>). Start with policy none and a report address (rua), read the reports, then move to quarantine and reject once every legitimate sender passes SPF or DKIM aligned. Free, no network. / Monta o registro DMARC; comece com p=none e suba para quarantine e reject.

{
  "type": "object",
  "properties": {
    "domain": {
      "type": "string",
      "description": "The domain, to name the record"
    },
    "policy": {
      "type": "string",
      "enum": [
        "none",
        "quarantine",
        "reject"
      ]
    },
    "rua": {
      "description": "Address for the aggregate reports",
      "type": "string"
    },
    "pct": {
      "type": "integer",
      "minimum": 1,
      "maximum": 100
    },
    "subdomain_policy": {
      "type": "string",
      "enum": [
        "none",
        "quarantine",
        "reject"
      ]
    }
  },
  "required": [
    "domain",
    "policy"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}