diff --git a/frontend_tests/node_tests/narrow.js b/frontend_tests/node_tests/narrow.js
index 8df07738ea..3fc5398443 100644
--- a/frontend_tests/node_tests/narrow.js
+++ b/frontend_tests/node_tests/narrow.js
@@ -14,6 +14,18 @@ function set_filter(operators) {
     narrow_state.set_current_filter(new Filter(operators));
 }
 
+var alice = {
+    email: 'alice@example.com',
+    user_id: 23,
+    full_name: 'Alice Smith',
+};
+
+var ray = {
+    email: 'ray@example.com',
+    user_id: 22,
+    full_name: 'Raymond',
+};
+
 run_test('stream_topic', () => {
     set_filter([['stream', 'Foo'], ['topic', 'Bar'], ['search', 'Yo']]);
 
@@ -46,18 +58,7 @@ run_test('stream_topic', () => {
 });
 
 run_test('uris', () => {
-    var ray = {
-        email: 'ray@example.com',
-        user_id: 22,
-        full_name: 'Raymond',
-    };
     people.add(ray);
-
-    var alice = {
-        email: 'alice@example.com',
-        user_id: 23,
-        full_name: 'Alice Smith',
-    };
     people.add(alice);
 
     var uri = narrow.pm_with_uri(ray.email);
@@ -122,10 +123,16 @@ run_test('show_empty_narrow_message', () => {
     assert.equal(hide_id,'.empty_feed_notice');
     assert.equal(show_id, '#no_unread_narrow_message');
 
+    set_filter([['pm-with', ['Yo']]]);
+    narrow.show_empty_narrow_message();
+    assert.equal(hide_id,'.empty_feed_notice');
+    assert.equal(show_id, '#non_existing_user');
+
+    people.add_in_realm(alice);
     set_filter([['pm-with', ['alice@example.com', 'Yo']]]);
     narrow.show_empty_narrow_message();
     assert.equal(hide_id,'.empty_feed_notice');
-    assert.equal(show_id, '#empty_narrow_multi_private_message');
+    assert.equal(show_id, '#non_existing_users');
 
     set_filter([['pm-with', 'alice@example.com']]);
     narrow.show_empty_narrow_message();
diff --git a/frontend_tests/node_tests/people.js b/frontend_tests/node_tests/people.js
index a02868288a..d425fef260 100644
--- a/frontend_tests/node_tests/people.js
+++ b/frontend_tests/node_tests/people.js
@@ -700,6 +700,8 @@ run_test('initialize', () => {
     assert(people.is_valid_email_for_compose('alice@example.com'));
     assert(!people.is_valid_email_for_compose('retiree@example.com'));
     assert(!people.is_valid_email_for_compose('totally-bogus-username@example.com'));
+    assert(people.is_valid_bulk_emails_for_compose(['bot@example.com', 'alice@example.com']));
+    assert(!people.is_valid_bulk_emails_for_compose(['not@valid.com', 'alice@example.com']));
     assert(people.is_my_user_id(42));
 
     var fetched_retiree = people.get_person_from_user_id(15);
diff --git a/static/js/narrow.js b/static/js/narrow.js
index b55cf2268e..bb178f997d 100644
--- a/static/js/narrow.js
+++ b/static/js/narrow.js
@@ -683,6 +683,12 @@ function pick_empty_narrow_banner() {
         // You are narrowed to empty search results.
         return $("#empty_search_narrow_message");
     } else if (first_operator === "pm-with") {
+        if (!people.is_valid_bulk_emails_for_compose(first_operand.split(','))) {
+            if (first_operand.indexOf(',') === -1) {
+                return $("#non_existing_user");
+            }
+            return $("#non_existing_users");
+        }
         if (first_operand.indexOf(',') === -1) {
             // You have no private messages with this person
             return $("#empty_narrow_private_message");
diff --git a/static/js/narrow_state.js b/static/js/narrow_state.js
index de665eeada..32dbf4a4ef 100644
--- a/static/js/narrow_state.js
+++ b/static/js/narrow_state.js
@@ -90,13 +90,7 @@ exports.set_compose_defaults = function () {
 
     if (single.has('pm-with')) {
         var private_message_recipient = single.get('pm-with');
-        var is_valid_op = _.every(private_message_recipient.split(','), function (op) {
-            if (!people.is_valid_email_for_compose(op)) {
-                return false;
-            }
-            return true;
-        });
-        if (is_valid_op) {
+        if (people.is_valid_bulk_emails_for_compose(private_message_recipient.split(','))) {
             opts.private_message_recipient = private_message_recipient;
         }
     }
diff --git a/static/js/people.js b/static/js/people.js
index 216d5f8d82..870e723962 100644
--- a/static/js/people.js
+++ b/static/js/people.js
@@ -571,6 +571,16 @@ exports.is_valid_email_for_compose = function (email) {
     return active_user_dict.has(person.user_id);
 };
 
+exports.is_valid_bulk_emails_for_compose = function (emails) {
+    // Returns false if at least one of the emails is invalid.
+    return _.every(emails, function (email) {
+        if (!people.is_valid_email_for_compose(email)) {
+            return false;
+        }
+        return true;
+    });
+};
+
 exports.get_active_user_for_email = function (email) {
     var person = people.get_by_email(email);
     if (!person) {
diff --git a/templates/zerver/app/home.html b/templates/zerver/app/home.html
index aa11d3ed22..d9673c7ae3 100644
--- a/templates/zerver/app/home.html
+++ b/templates/zerver/app/home.html
@@ -84,6 +84,9 @@
     <div id="non_existing_user" class="empty_feed_notice">
         <h4>{{ _("This user does not exist!") }}</h4>
     </div>
+    <div id="non_existing_users" class="empty_feed_notice">
+        <h4>{{ _("One or more of these users do not exist!") }}</h4>
+    </div>
     <div id="nonsubbed_stream_narrow_message" class="empty_feed_notice">
         <h4>{{ _("You aren't subscribed to this stream and nobody has talked about that yet!") }}</h4>
         <div class="sub_button_row new-style">