diff --git a/ietf/api/tests.py b/ietf/api/tests.py
index 23e9ff01038..809b45cc2b3 100644
--- a/ietf/api/tests.py
+++ b/ietf/api/tests.py
@@ -1164,6 +1164,39 @@ def test_active_email_list(self):
         self.assertCountEqual(result.keys(), ["addresses"])
         self.assertCountEqual(result["addresses"], Email.objects.filter(active=True).values_list("address", flat=True))
 
+    @override_settings(APP_API_TOKENS={"ietf.api.views.related_email_list": ["valid-token"]})
+    def test_related_email_list(self):
+        joe = EmailFactory(address='joe@work.com')
+        EmailFactory(address='joe@home.com', person=joe.person)
+        EmailFactory(address='jòe@spain.com', person=joe.person)
+        url = urlreverse("ietf.api.views.related_email_list", kwargs={'email': 'joe@home.com'})
+        # no api key
+        r = self.client.get(url, headers={})
+        self.assertEqual(r.status_code, 403)
+        # invalid api key
+        r = self.client.get(url, headers={"X-Api-Key": "not-the-valid-token"})
+        self.assertEqual(r.status_code, 403)
+        # wrong method
+        r = self.client.post(url, headers={"X-Api-Key": "valid-token"})
+        self.assertEqual(r.status_code, 405)
+        # valid
+        r = self.client.get(url, headers={"X-Api-Key": "valid-token"})
+        self.assertEqual(r.status_code, 200)
+        self.assertEqual(r.headers["Content-Type"], "application/json")
+        result = json.loads(r.content)
+        self.assertCountEqual(result.keys(), ["addresses"])
+        self.assertCountEqual(result["addresses"], joe.person.email_set.exclude(address='joe@home.com').values_list("address", flat=True))
+        # non-ascii
+        non_ascii_url = urlreverse("ietf.api.views.related_email_list", kwargs={'email': 'jòe@spain.com'})
+        r = self.client.get(non_ascii_url, headers={"X-Api-Key": "valid-token"})
+        self.assertEqual(r.status_code, 200)
+        result = json.loads(r.content)
+        self.assertTrue('joe@home.com' in result["addresses"])
+        # email not found
+        not_found_url = urlreverse("ietf.api.views.related_email_list", kwargs={'email': 'nobody@nowhere.com'})
+        r = self.client.get(not_found_url, headers={"X-Api-Key": "valid-token"})
+        self.assertEqual(r.status_code, 404)
+
     @override_settings(APP_API_TOKENS={"ietf.api.views.role_holder_addresses": ["valid-token"]})
     def test_role_holder_addresses(self):
         url = urlreverse("ietf.api.views.role_holder_addresses")
diff --git a/ietf/api/urls.py b/ietf/api/urls.py
index 2fcaba60942..bafd5c5b761 100644
--- a/ietf/api/urls.py
+++ b/ietf/api/urls.py
@@ -73,6 +73,8 @@
     url(r'^openid/', include('oidc_provider.urls', namespace='oidc_provider')),
     # Email alias listing
     url(r'^person/email/$', api_views.active_email_list),
+    # Related Email listing
+    url(r'^person/email/(?P<email>[^/\x00]+)/related/$', api_views.related_email_list),
     # Draft submission API
     url(r'^submit/?$', submit_views.api_submit_tombstone),
     # Draft upload API
diff --git a/ietf/api/views.py b/ietf/api/views.py
index e5b1f96aed8..97b97930482 100644
--- a/ietf/api/views.py
+++ b/ietf/api/views.py
@@ -691,6 +691,31 @@ def active_email_list(request):
     return HttpResponse(status=405)
 
 
+@requires_api_token
+@csrf_exempt
+def related_email_list(request, email):
+    """Given an email address, returns all other email addresses known
+    to Datatracker, via Person object
+    """
+    def _http_err(code, text):
+        return HttpResponse(text, status=code, content_type="text/plain")
+
+    if request.method == "GET":
+        try:
+            email_obj = Email.objects.get(address=email)
+        except Email.DoesNotExist:
+            return _http_err(404, "Email not found")
+        person = email_obj.person
+        if not person:
+            return JsonResponse({"addresses": []})
+        return JsonResponse(
+            {
+                "addresses": list(person.email_set.exclude(address=email).values_list("address", flat=True)),
+            }
+        )
+    return HttpResponse(status=405)
+
+
 @requires_api_token
 def role_holder_addresses(request):
     if request.method == "GET":