diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 06cc4a4fe7..e3d5835e35 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -597,8 +597,13 @@ def recipient_for_emails(emails, not_forged_mirror_message,
 
     # Prevent cross realm private messages unless it is between only two realms
     # and one of users is a zuliper
-    if len(realm_domains) == 2 and not (normalized_emails & settings.OG_ZULIPER_EMAILS):
-        raise ValidationError("You can't send private messages outside of your organization.")
+    if len(realm_domains) == 2:
+        # I'm assuming that cross-realm PMs with the "admin realm" are rare, and therefore can be slower
+        admin_realm = Realm.objects.get(domain=settings.ADMIN_DOMAIN)
+        admin_realm_admin_emails = [u.email for u in admin_realm.get_admin_users()]
+        # We allow settings.CROSS_REALM_BOT_EMAILS for the hardcoded emails for the feedback and notification bots
+        if not (normalized_emails & admin_realm_admin_emails or normalized_emails & settings.CROSS_REALM_BOT_EMAILS):
+            raise ValidationError("You can't send private messages outside of your organization.")
     if len(realm_domains) > 2:
         raise ValidationError("You can't send private messages outside of your organization.")
 
diff --git a/zerver/test_messages.py b/zerver/test_messages.py
index 0fecddce1d..e5a45928f9 100644
--- a/zerver/test_messages.py
+++ b/zerver/test_messages.py
@@ -157,7 +157,7 @@ class IncludeHistoryTest(AuthedTestCase):
 
 class TestCrossRealmPMs(AuthedTestCase):
     def setUp(self):
-        settings.OG_ZULIPER_EMAILS.add('test-og-user@zulip.com')
+        settings.CROSS_REALM_BOT_EMAILS.add('test-og-bot@zulip.com')
 
     def create_user(self, email):
         username, domain = email.split('@')
@@ -225,7 +225,7 @@ class TestCrossRealmPMs(AuthedTestCase):
         deployment = Deployment.objects.filter()[0]
         deployment.realms.add(r1)
 
-        user1_email = 'test-og-user@zulip.com'
+        user1_email = 'test-og-bot@zulip.com'
         user1 = self.create_user(user1_email)
         user2_email = 'user2@1.example.com'
         user2 = self.create_user(user2_email)
@@ -244,7 +244,7 @@ class TestCrossRealmPMs(AuthedTestCase):
 
         user1_email = 'user1@1.example.com'
         user1 = self.create_user(user1_email)
-        user2_email = 'test-og-user@zulip.com'
+        user2_email = 'test-og-bot@zulip.com'
         user2 = self.create_user(user2_email)
 
         self.send_message(user1_email, user2_email, Recipient.PERSONAL)
@@ -265,7 +265,7 @@ class TestCrossRealmPMs(AuthedTestCase):
         self.create_user(user1_email)
         user2_email = 'user2@2.example.com'
         self.create_user(user2_email)
-        user3_email = 'test-og-user@zulip.com'
+        user3_email = 'test-og-bot@zulip.com'
         self.create_user(user3_email)
 
         with self.assertRaisesRegexp(JsonableError,
diff --git a/zproject/settings.py b/zproject/settings.py
index 14862d08d6..a56eab4a4c 100644
--- a/zproject/settings.py
+++ b/zproject/settings.py
@@ -932,5 +932,4 @@ USING_EMBEDLY = False
 # This is a debugging option only
 PROFILE_ALL_REQUESTS = False
 
-OG_ZULIPER_EMAILS = set(('feedback@zulip.com', 'notification-bot@zulip.com',
-))
+CROSS_REALM_BOT_EMAILS = set(('feedback@zulip.com', 'notification-bot@zulip.com'))