diff --git a/app/components/lobbyside-widget/index.hbs b/app/components/lobbyside-widget/index.hbs
index 63a4772d58..57a634b5d8 100644
--- a/app/components/lobbyside-widget/index.hbs
+++ b/app/components/lobbyside-widget/index.hbs
@@ -25,6 +25,7 @@
       this.customFields.stages_completed
       this.customFields.signed_up_date
       this.customFields.subscription_type
+      this.customFields.other_emails
     }}
     {{will-destroy this.removeScript}}
   ></div>
diff --git a/app/components/lobbyside-widget/index.ts b/app/components/lobbyside-widget/index.ts
index a33cfaab73..7961d40ca5 100644
--- a/app/components/lobbyside-widget/index.ts
+++ b/app/components/lobbyside-widget/index.ts
@@ -15,6 +15,7 @@ declare global {
         stages_completed: string;
         signed_up_date: string;
         subscription_type: string;
+        other_emails: string;
       }): void;
     };
   }
@@ -30,12 +31,15 @@ interface VisitorSource {
   hasActiveSubscription?: boolean;
   teamHasActiveSubscription?: boolean;
   courseParticipations?: { completedStageSlugs?: string[] }[];
+  primaryEmailAddress?: string | null;
+  emailAddresses?: { value?: string | null }[];
 }
 
 export interface LobbysideCustomFields {
   stages_completed: string;
   signed_up_date: string;
   subscription_type: string;
+  other_emails: string;
 }
 
 function subscriptionType(user: VisitorSource | null | undefined): string {
@@ -62,6 +66,21 @@ function subscriptionType(user: VisitorSource | null | undefined): string {
   return 'free';
 }
 
+function otherEmails(user: VisitorSource | null | undefined): string {
+  const primary = (user?.primaryEmailAddress ?? '').trim();
+  const seen = new Set<string>();
+
+  for (const entry of user?.emailAddresses ?? []) {
+    const value = (entry?.value ?? '').trim();
+
+    if (value && value !== primary) {
+      seen.add(value);
+    }
+  }
+
+  return Array.from(seen).join(', ');
+}
+
 export function lobbysideCustomFields(user: VisitorSource | null | undefined): LobbysideCustomFields {
   const stagesCompleted = (user?.courseParticipations ?? []).reduce(
     (sum, participation) => sum + (participation.completedStageSlugs?.length ?? 0),
@@ -72,6 +91,7 @@ export function lobbysideCustomFields(user: VisitorSource | null | undefined): L
     stages_completed: String(stagesCompleted),
     signed_up_date: user?.createdAt ? user.createdAt.toISOString().slice(0, 10) : '',
     subscription_type: subscriptionType(user),
+    other_emails: otherEmails(user),
   };
 }
 
diff --git a/app/services/authenticator.ts b/app/services/authenticator.ts
index ade1e9a669..486303a503 100644
--- a/app/services/authenticator.ts
+++ b/app/services/authenticator.ts
@@ -118,6 +118,8 @@ export default class AuthenticatorService extends Service {
       'affiliate-links.user',
       // Powers the `stages_completed` field the Lobbyside widget pushes via setVisitor.
       'course-participations',
+      // Powers the `other_emails` field the Lobbyside widget pushes via setVisitor.
+      'email-addresses',
       'feature-suggestions',
       'promotional-discounts',
       'promotional-discounts.affiliate-referral',
diff --git a/tests/unit/components/lobbyside-widget-test.ts b/tests/unit/components/lobbyside-widget-test.ts
index fd8994d7ac..ba91341f36 100644
--- a/tests/unit/components/lobbyside-widget-test.ts
+++ b/tests/unit/components/lobbyside-widget-test.ts
@@ -20,6 +20,7 @@ module('Unit | Component | lobbyside-widget', function () {
       stages_completed: '0',
       signed_up_date: '',
       subscription_type: '',
+      other_emails: '',
     });
   });
 
@@ -57,4 +58,37 @@ module('Unit | Component | lobbyside-widget', function () {
 
     assert.strictEqual(lobbysideCustomFields(createUser()).subscription_type, 'free');
   });
+
+  test('other_emails joins every non-primary email, comma-separated', function (assert) {
+    const user = createUser({
+      primaryEmailAddress: 'primary@example.com',
+      emailAddresses: [{ value: 'primary@example.com' }, { value: 'work@example.com' }, { value: 'school@example.com' }],
+    } as unknown as Partial<UserModel>);
+
+    assert.strictEqual(lobbysideCustomFields(user).other_emails, 'work@example.com, school@example.com');
+  });
+
+  test('other_emails excludes the primary email and is empty when it is the only one', function (assert) {
+    const user = createUser({
+      primaryEmailAddress: 'primary@example.com',
+      emailAddresses: [{ value: 'primary@example.com' }],
+    } as unknown as Partial<UserModel>);
+
+    assert.strictEqual(lobbysideCustomFields(user).other_emails, '');
+  });
+
+  test('other_emails dedupes and drops blank values', function (assert) {
+    const user = createUser({
+      primaryEmailAddress: 'primary@example.com',
+      emailAddresses: [{ value: 'work@example.com' }, { value: '  work@example.com  ' }, { value: '' }, { value: 'alt@example.com' }],
+    } as unknown as Partial<UserModel>);
+
+    assert.strictEqual(lobbysideCustomFields(user).other_emails, 'work@example.com, alt@example.com');
+  });
+
+  test('other_emails is empty when the user has no email addresses', function (assert) {
+    const user = createUser({ primaryEmailAddress: 'primary@example.com', emailAddresses: [] } as unknown as Partial<UserModel>);
+
+    assert.strictEqual(lobbysideCustomFields(user).other_emails, '');
+  });
 });