diff --git a/app/mailers/user_notifications.rb b/app/mailers/user_notifications.rb
index a3450b00d6a..3d2de7cb49d 100644
--- a/app/mailers/user_notifications.rb
+++ b/app/mailers/user_notifications.rb
@@ -224,8 +224,8 @@ class UserNotifications < ActionMailer::Base
         @counts << { label_key: 'user_notifications.digest.liked_received', value: value, href: "#{Discourse.base_url}/my/notifications" } if value > 0
       end
 
-      if @counts.size < 3
-        value = User.real.where(active: true, staged: false).not_suspended.where("created_at > ?", min_date).count
+      if @counts.size < 3 && user.user_option.digest_after_minutes >= 1440
+        value = summary_new_users_count(min_date)
         @counts << { label_key: 'user_notifications.digest.new_users', value: value, href: "#{Discourse.base_url}/about" } if value > 0
       end
 
@@ -676,4 +676,18 @@ class UserNotifications < ActionMailer::Base
     @unsubscribe_key = UnsubscribeKey.create_key_for(@user, "digest")
     @disable_email_custom_styles = !SiteSetting.apply_custom_styles_to_digest
   end
+
+  def self.summary_new_users_count_key(min_date_str)
+    "summary-new-users:#{min_date_str}"
+  end
+
+  def summary_new_users_count(min_date)
+    min_date_str = min_date.is_a?(String) ? min_date : min_date.strftime('%Y-%m-%d')
+    key = self.class.summary_new_users_count_key(min_date_str)
+    ((count = $redis.get(key)) && count.to_i) || begin
+      count = User.real.where(active: true, staged: false).not_suspended.where("created_at > ?", min_date_str).count
+      $redis.setex(key, 1.day, count)
+      count
+    end
+  end
 end
diff --git a/spec/mailers/user_notifications_spec.rb b/spec/mailers/user_notifications_spec.rb
index f0640a0335d..34cffcbe585 100644
--- a/spec/mailers/user_notifications_spec.rb
+++ b/spec/mailers/user_notifications_spec.rb
@@ -107,6 +107,10 @@ describe UserNotifications do
 
     subject { UserNotifications.digest(user) }
 
+    after do
+      $redis.keys('summary-new-users:*').each { |key| $redis.del(key) }
+    end
+
     context "without new topics" do
 
       it "doesn't send the email" do
@@ -138,6 +142,19 @@ describe UserNotifications do
         expect(subject.html_part.body.to_s).to be_present
         expect(subject.text_part.body.to_s).to be_present
         expect(subject.header["List-Unsubscribe"].to_s).to match(/\/email\/unsubscribe\/\h{64}/)
+        expect(subject.html_part.body.to_s).to include('New Users')
+      end
+
+      it "doesn't include new user count if digest_after_minutes is low" do
+        user.user_option.digest_after_minutes = 60
+        expect(subject.html_part.body.to_s).to_not include('New Users')
+      end
+
+      it "works with min_date string" do
+        digest = UserNotifications.digest(user, since: 1.month.ago.to_date.to_s)
+        expect(digest.html_part.body.to_s).to be_present
+        expect(digest.text_part.body.to_s).to be_present
+        expect(digest.html_part.body.to_s).to include('New Users')
       end
 
       it "includes email_prefix in email subject instead of site title" do