@well-known-js/mta-sts

Generate an RFC 8461 SMTP MTA-STS policy at /.well-known/mta-sts.txt.

Installation

pnpm add @well-known-js/core @well-known-js/mta-sts

Usage

import { defineConfig } from "@well-known-js/core";
import { mtaSts } from "@well-known-js/mta-sts";

export default defineConfig({
	providers: [
		mtaSts({
			version: "STSv1",
			mode: "enforce",
			mx: ["mail.example.com", "*.example.net"],
			maxAge: 604_800,
		}),
	],
});

The generated policy uses the RFC-required CRLF line endings. mx is required in enforce and testing modes and optional in none mode. maxAge is expressed in seconds and capped at the RFC limit of 31,557,600. Internationalized MX names must be supplied as Punycode A-labels.