email-validator-dns-provider-rules

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)

Invalid emails that other validators pass:

email	reason
[e-mail]	Gmail don't allows "_" and "-" symbols
[e-mail]	"8avymt4v93mvt3t03.com" isn't real domain and dont have DNS MX records
s!o#m$e%o^n&[e-mail]	99.99% public email providers allow only "a-z","0-9",".","_","-","+" before "@" part
[e-mail]	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('[e-mail]')) {
    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 INVALID_REASON_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('[e-mail]', yourBlocklistDomains);

Passing your DOH provider

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

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

Testing

npm test

generating d.ts

tsc --declaration src/index.js --allowJs

NPM package

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