Normalize fastmail alias subdomains

Author: horgh

CHANGELOG.md

@@ -10,6 +10,9 @@ CHANGELOG
 * Periods are now removed from `gmail.com` email address local parts when
   `hashAddress` is used. For example, `[email protected]` will become
   `[email protected]`.
+* Fastmail alias subdomain email addresses are now normalized when
+  `hashAddress` is used. For example, `[email protected]` will become
+  `[email protected]`.
 
 6.0.0 (2023-12-05)
 ------------------

src/request/email.spec.ts

@@ -158,6 +158,16 @@ describe('Email()', () => {
       md5: md5('[email protected]'),
       domain: 'gmail.com',
     },
+    {
+      email: '[email protected]',
+      md5: md5('[email protected]'),
+      domain: 'user.fastmail.com',
+    },
+    {
+      email: '[email protected]',
+      md5: md5('[email protected]'),
+      domain: 'bar.example.com',
+    },
   ];
 
   test.each(normalizeTests)('%p', (arg) => {

src/request/email.ts

@@ -56,6 +56,126 @@ export default class Email implements EmailProps {
     'ya.ru': 'yandex.ru',
   };
 
+  private static readonly fastmailDomains: { [key: string]: boolean } = {
+    '123mail.org': true,
+    '150mail.com': true,
+    '150ml.com': true,
+    '16mail.com': true,
+    '2-mail.com': true,
+    '4email.net': true,
+    '50mail.com': true,
+    'airpost.net': true,
+    'allmail.net': true,
+    'bestmail.us': true,
+    'cluemail.com': true,
+    'elitemail.org': true,
+    'emailcorner.net': true,
+    'emailengine.net': true,
+    'emailengine.org': true,
+    'emailgroups.net': true,
+    'emailplus.org': true,
+    'emailuser.net': true,
+    'eml.cc': true,
+    'f-m.fm': true,
+    'fast-email.com': true,
+    'fast-mail.org': true,
+    'fastem.com': true,
+    'fastemail.us': true,
+    'fastemailer.com': true,
+    'fastest.cc': true,
+    'fastimap.com': true,
+    'fastmail.cn': true,
+    'fastmail.co.uk': true,
+    'fastmail.com': true,
+    'fastmail.com.au': true,
+    'fastmail.de': true,
+    'fastmail.es': true,
+    'fastmail.fm': true,
+    'fastmail.fr': true,
+    'fastmail.im': true,
+    'fastmail.in': true,
+    'fastmail.jp': true,
+    'fastmail.mx': true,
+    'fastmail.net': true,
+    'fastmail.nl': true,
+    'fastmail.org': true,
+    'fastmail.se': true,
+    'fastmail.to': true,
+    'fastmail.tw': true,
+    'fastmail.uk': true,
+    'fastmail.us': true,
+    'fastmailbox.net': true,
+    'fastmessaging.com': true,
+    'fea.st': true,
+    'fmail.co.uk': true,
+    'fmailbox.com': true,
+    'fmgirl.com': true,
+    'fmguy.com': true,
+    'ftml.net': true,
+    'h-mail.us': true,
+    'hailmail.net': true,
+    'imap-mail.com': true,
+    'imap.cc': true,
+    'imapmail.org': true,
+    'inoutbox.com': true,
+    'internet-e-mail.com': true,
+    'internet-mail.org': true,
+    'internetemails.net': true,
+    'internetmailing.net': true,
+    'jetemail.net': true,
+    'justemail.net': true,
+    'letterboxes.org': true,
+    'mail-central.com': true,
+    'mail-page.com': true,
+    'mailandftp.com': true,
+    'mailas.com': true,
+    'mailbolt.com': true,
+    'mailc.net': true,
+    'mailcan.com': true,
+    'mailforce.net': true,
+    'mailftp.com': true,
+    'mailhaven.com': true,
+    'mailingaddress.org': true,
+    'mailite.com': true,
+    'mailmight.com': true,
+    'mailnew.com': true,
+    'mailsent.net': true,
+    'mailservice.ms': true,
+    'mailup.net': true,
+    'mailworks.org': true,
+    'ml1.net': true,
+    'mm.st': true,
+    'myfastmail.com': true,
+    'mymacmail.com': true,
+    'nospammail.net': true,
+    'ownmail.net': true,
+    'petml.com': true,
+    'postinbox.com': true,
+    'postpro.net': true,
+    'proinbox.com': true,
+    'promessage.com': true,
+    'realemail.net': true,
+    'reallyfast.biz': true,
+    'reallyfast.info': true,
+    'rushpost.com': true,
+    'sent.as': true,
+    'sent.at': true,
+    'sent.com': true,
+    'speedpost.net': true,
+    'speedymail.org': true,
+    'ssl-mail.com': true,
+    'swift-mail.com': true,
+    'the-fastest.net': true,
+    'the-quickest.com': true,
+    'theinternetemail.com': true,
+    'veryfast.biz': true,
+    'veryspeedy.net': true,
+    'warpmail.net': true,
+    'xsmail.com': true,
+    'yepmail.net': true,
+    'your-mail.com': true,
+  };
+
   public constructor(email: EmailProps) {
     if (email.address != null && !isEmail(email.address)) {
       throw new ArgumentError('`email.address` is an invalid email address');
@@ -106,6 +226,22 @@ export default class Email implements EmailProps {
       localPart = localPart.replace(/\./g, '');
     }
 
+    const domainParts = domain.split('.');
+    if (domainParts.length > 2) {
+      const possibleDomain = domainParts.slice(1).join('.');
+      if (
+        Object.prototype.hasOwnProperty.call(
+          Email.fastmailDomains,
+          possibleDomain
+        )
+      ) {
+        domain = possibleDomain;
+        if (localPart !== '') {
+          localPart = domainParts[0];
+        }
+      }
+    }
+
     return localPart + '@' + domain;
   }