feat: Add forwarding domains as verification check

apps/api/src/services/EmailVerificationService.ts

@@ -8,6 +8,35 @@ const DISPOSABLE_DOMAINS_URL =
 const DISPOSABLE_DOMAINS_CACHE_KEY = 'email:disposable_domains';
 const CACHE_TTL_SECONDS = 24 * 60 * 60; // 24 hours (list updates daily)
 
+// Known email forwarding/alias services
+const FORWARDING_DOMAINS = new Set([
+  'privaterelay.appleid.com', // Apple Sign In
+  'mozmail.com', // Firefox Relay
+  'simplelogin.com', // SimpleLogin
+  'simplelogin.fr',
+  'simplelogin.co',
+  'simplelogin.io',
+  'aleeas.com',
+  'slmail.me',
+  'dralias.com',
+  '8shield.net',
+  'anonaddy.com', // Addy.io
+  'anonaddy.me',
+  'addy.io',
+  'duck.com', // DuckDuckGo
+  '33mail.com', // 33mail
+  '33m.co',
+  'passmail.com', // Proton Pass
+  'passmail.net',
+  'passinbox.com',
+  'passfwd.com',
+  'y.yo.fr',
+  'opayq.com', // IronVest (formerly Blur)
+  'cloak.id', // Cloaked
+  'erine.email', // Erine
+  'use.startmail.com', // StartMail
+]);
+
 export class EmailVerificationService {
   private static disposableDomainsSet: Set<string> | null = null;
 
@@ -16,6 +45,7 @@ export class EmailVerificationService {
    * - Checks if domain exists (DNS A/AAAA records)
    * - Checks for MX records
    * - Detects disposable email addresses
+   * - Detects forwarding/alias email addresses
    * - Suggests corrections for common typos
    */
   static async verifyEmail(email: string): Promise<EmailVerificationResult> {
@@ -23,6 +53,7 @@ export class EmailVerificationService {
       email,
       valid: true,
       isDisposable: false,
+      isAlias: false,
       isTypo: false,
       isPlusAddressed: false,
       domainExists: false,
@@ -43,6 +74,9 @@ export class EmailVerificationService {
     // Check if email is from a disposable domain using GitHub list
     result.isDisposable = await this.isDisposableDomain(domain);
 
+    // Check if email is from a known forwarding/alias service
+    result.isAlias = this.isForwardingDomain(domain);
+
     // Check for plus addressing
     result.isPlusAddressed = emailParts[0]!.includes('+');
 
@@ -146,4 +180,11 @@ export class EmailVerificationService {
     const disposableDomains = await this.getDisposableDomains();
     return disposableDomains.has(domain.toLowerCase());
   }
+
+  /**
+   * Check if a domain is a known forwarding/alias service
+   */
+  private static isForwardingDomain(domain: string): boolean {
+    return FORWARDING_DOMAINS.has(domain.toLowerCase());
+  }
 }

apps/landing/src/components/tools/EmailVerificationResult.tsx

@@ -1,4 +1,15 @@
-import {AlertCircle, AlertTriangle, CheckCircle, Info, Mail, Server, Shield, Trash2, XCircle} from 'lucide-react';
+import {
+  AlertCircle,
+  AlertTriangle,
+  CheckCircle,
+  Info,
+  Mail,
+  Server,
+  Shield,
+  Trash2,
+  XCircle,
+  Forward,
+} from 'lucide-react';
 import type {EmailVerificationResult as VerificationResult} from '../../lib/emailVerification';
 
 interface EmailVerificationResultProps {
@@ -83,6 +94,22 @@ export function EmailVerificationResult({result}: EmailVerificationResultProps)
             )}
           </div>
 
+          {/* Alias/Forwarding Email */}
+          <div className="flex items-center justify-between px-6 py-4">
+            <div className="flex items-center gap-3">
+              <Forward className="h-5 w-5 text-neutral-600" />
+              <div>
+                <p className="font-medium text-neutral-900">Forwarding Service</p>
+                <p className="text-sm text-neutral-600">Email alias/forwarding detected</p>
+              </div>
+            </div>
+            {result.isAlias ? (
+              <Info className="h-5 w-5 text-blue-600" />
+            ) : (
+              <CheckCircle className="h-5 w-5 text-green-600" />
+            )}
+          </div>
+
           {/* Typo Detection */}
           <div className="flex items-center justify-between px-6 py-4">
             <div className="flex items-center gap-3">

apps/landing/src/lib/emailVerification.ts

@@ -2,6 +2,7 @@ export interface EmailVerificationResult {
   email: string;
   valid: boolean;
   isDisposable: boolean;
+  isAlias: boolean;
   isTypo: boolean;
   isPlusAddressed: boolean;
   domainExists: boolean;

apps/wiki/openapi.json

@@ -664,6 +664,10 @@
                           "type": "boolean",
                           "description": "Whether the email is from a disposable/temporary email domain"
                         },
+                        "isAlias": {
+                          "type": "boolean",
+                          "description": "Whether the email is from a forwarding/alias service"
+                        },
                         "isTypo": {
                           "type": "boolean",
                           "description": "Whether a potential typo was detected in the email address"
@@ -698,6 +702,7 @@
                         "email",
                         "valid",
                         "isDisposable",
+                        "isAlias",
                         "isTypo",
                         "isPlusAddressed",
                         "domainExists",
@@ -716,6 +721,7 @@
                         "email": "[email protected]",
                         "valid": true,
                         "isDisposable": false,
+                        "isAlias": false,
                         "isTypo": false,
                         "isPlusAddressed": false,
                         "domainExists": true,
@@ -732,6 +738,7 @@
                         "email": "[email protected]",
                         "valid": false,
                         "isDisposable": false,
+                        "isAlias": false,
                         "isTypo": true,
                         "isPlusAddressed": false,
                         "domainExists": false,
@@ -749,6 +756,7 @@
                         "email": "[email protected]",
                         "valid": true,
                         "isDisposable": true,
+                        "isAlias": false,
                         "isTypo": false,
                         "isPlusAddressed": false,
                         "domainExists": true,

packages/types/src/api/verification.ts

@@ -9,6 +9,7 @@ export interface EmailVerificationResult {
   email: string;
   valid: boolean;
   isDisposable: boolean;
+  isAlias: boolean;
   isTypo: boolean;
   isPlusAddressed: boolean;
   domainExists: boolean;