Block integer local-part emails in emailIsBad

src/utils/resend.test.ts

@@ -51,6 +51,11 @@ describe('emailIsBad', () => {
     expect(result).toBe(true);
   });
 
+  it('should return true for emails with an integer local part', () => {
+    const result = emailIsBad('123456@example.com');
+    expect(result).toBe(true);
+  });
+
   it('should return false for legitimate email domains', () => {
     const legitimateEmails = [
       'user@gmail.com',
@@ -163,6 +168,11 @@ describe('fakeSubscribe', () => {
     const result = await fakeSubscribe({ email: '4@apexgunparts.space' });
     expect(result).toEqual({ success: true });
   });
+
+  it('should return success for integer local part emails', async () => {
+    const result = await fakeSubscribe({ email: '123@example.com' });
+    expect(result).toEqual({ success: true });
+  });
 });
 
 describe('isContactEvent', () => {
@@ -475,6 +485,23 @@ describe('subscribe', () => {
     expect(resend.contacts.create).not.toHaveBeenCalled();
   });
 
+  it('should return fake response for integer local part emails', async () => {
+    const badSubscriber = {
+      email: '999@example.com',
+      firstName: 'Spam',
+      lastName: 'Bot',
+    };
+
+    const result = await subscribe(badSubscriber);
+    expect(result).toEqual({
+      data: {
+        id: '123',
+      },
+      error: null,
+    });
+    expect(resend.contacts.create).not.toHaveBeenCalled();
+  });
+
   it('should create contact for legitimate emails when contact does not exist', async () => {
     const legitimateSubscriber = {
       email: 'user@example.com',

src/utils/resend.ts

@@ -238,8 +238,10 @@ export const getSubscriberCount = async () => {
 const BAD_DOMAINS = ['mailinator.com', 'abhoward.site', 'apexgunparts.space'];
 
 export const emailIsBad = (email: string) => {
+  const localPart = email.split('@')[0];
   const domain = email.split('@')[1]?.toLowerCase();
-  return BAD_DOMAINS.includes(domain);
+  const hasIntegerLocalPart = /^\d+$/.test(localPart);
+  return BAD_DOMAINS.includes(domain) || hasIntegerLocalPart;
 };
 
 /**