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MTA-STS and TLS-RPT Generator

Generate MTA-STS and TLS-RPT policy files for email security.

Output will appear here…

How to Use This Tool

  1. Fill in Domain, Mode, and MX Hosts (one per line). Each control is labeled; you do not need to paste a JSON blob.
  2. Click "Run" to run the tool in your browser.
  3. Read the result below the form and copy it if you need it in another app.

Learn More About MTA-STS and TLS-RPT Generator

About MTA-STS and TLS-RPT Generator

Generate MTA-STS policy files and TLS-RPT report configurations for email security.

About

Generate MTA-STS policy files and TLS-RPT report configurations for email security.
Generate MTA-STS policy files and TLS-RPT report configurations for email security.
Runs in browser
Yes
No signup required
Yes

Examples

Single MX enforce

Single MX enforce
Input
{
  "domain": "example.com",
  "mode": "enforce",
  "mx": "mail.example.com"
}
Output
── MTA-STS Policy ──
(Serve at https://example.com/.well-known/mta-sts.txt)

version: STSv1
mode: enforce
mx: mail.example.com
max_age: 604800

── TLS-RPT Record ──
(DNS TXT record: _smtp._tls.example.com)

{
  "contact": [
    "mailto:tlsrpt@example.com"
  ],
  "policies": [
    {
      "tlsa": {
        "mode": "STS",
        "mx_host": [
          "mail.example.com"
        ]
      }
    }
  ]
}

Multiple MX testing

Multiple MX testing
Input
{
  "domain": "example.org",
  "mode": "testing",
  "mx": "mail1.example.org\nmail2.example.org"
}
Output
── MTA-STS Policy ──
(Serve at https://example.org/.well-known/mta-sts.txt)

version: STSv1
mode: testing
mx: mail1.example.org
mx: mail2.example.org
max_age: 604800

── TLS-RPT Record ──
(DNS TXT record: _smtp._tls.example.org)

{
  "contact": [
    "mailto:tlsrpt@example.org"
  ],
  "policies": [
    {
      "tlsa": {
        "mode": "STS",
        "mx_host": [
          "mail1.example.org",
          "mail2.example.org"
        ]
      }
    }
  ]
}

None mode

None mode
Input
{
  "domain": "example.net",
  "mode": "none",
  "mx": ""
}
Output
── MTA-STS Policy ──
(Serve at https://example.net/.well-known/mta-sts.txt)

version: STSv1
mode: none
mx: mail.example.net
max_age: 604800

── TLS-RPT Record ──
(DNS TXT record: _smtp._tls.example.net)

{
  "contact": [
    "mailto:tlsrpt@example.net"
  ],
  "policies": [
    {
      "tlsa": {
        "mode": "STS",
        "mx_host": [
          "mail.example.net"
        ]
      }
    }
  ]
}

Use Cases

  • Check mta-sts and tls-rpt generator values while you draft a page, spreadsheet, or config.
  • Fill Domain, Mode, MX Hosts (one per line) and compare the result to a second source.
  • Keep sensitive inputs on-device — this page runs the calculation in the browser.

Frequently Asked Questions

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