Email validator dns provider rules

Email Validator with checking DNS MX records and strict real-life symbols rules

• more strict and realistic validation for symbols before "@"
• stricter specific rules for ESP like gmail, yahoo, etc
• check if domain really exist and works
• check if domain can receive emails (DNS MX record)
• your version of invalid reasons text
• passing your blocklist MX domains
• everything works in browser! (DNS query by DOH)
• works in Node.js via DNS library
• supports TypeScript and JavaScript

Invalid emails that other validators pass:

| email | reason | |-------------------------------|--------------------------------------------------------------------------------------| | [email protected] | Gmail don't allows "" and "-" symbols | | [email protected] | "8avymt4v93mvt3t03.com" isn't real domain and dont have DNS MX records | | s!o#m$e%o^n&[email protected] | 99.99% public email providers allow only "a-z","0-9",".","","-","+" before "@" part | | [email protected] | possibility of adding your blocklist of domains and MX domains |

Usage

npm install email-validator-dns-provider-rules --save

import { isValidEmail, getLastInvalidText } from "email-validator-dns-provider-rules";

if (!await isValidEmail('[email protected]')) {
    alert('Please correct your email: ' + getLastInvalidText());
}

Your version of invalid reasons text

You can use getLastInvalidReasonId() and make dictionary with your version of text:

const CUSTOM_INVALID_TEXT = {
    [INVALID_REASON_AMOUNT_OF_AT]: 'no @ symbol or too many of them',
    [INVALID_REASON_USERNAME_GENERAL_RULES]:
        'invalid username before @ by general email rules',
    [INVALID_REASON_DOMAIN_GENERAL_RULES]:
        'invalid domain after @ by general domain rules',
    [INVALID_REASON_NO_DNS_MX_RECORDS]: 'domain after @ has no DNS MX records',
    [INVALID_REASON_DOMAIN_IN_BLOCKLIST]: 'email domain is in blocklist',
    [INVALID_REASON_USERNAME_VENDOR_RULES]:
        'invalid username before @ by domain vendor rules',
};

Passing your blocklist domains

const yourBlocklistDomains = ['somedomain.com', '...'];
isValidEmail('[email protected]', yourBlocklistDomains);

Passing your DOH provider

You can choose other DNS over HTTPS provider or even create your own

isValidEmail('[email protected]', null, 'https://your-provider-site/dns-query');

Testing

npm test

generating d.ts

npm i -g typescript
tsc

NPM package

https://www.npmjs.com/package/email-validator-dns-provider-rules