Merge pull request #3527 from techAPJ/patch-3

FEATURE: include email_prefix in digest email subject instead of site title

app/mailers/user_notifications.rb

@@ -54,7 +54,7 @@ class UserNotifications < ActionMailer::Base
 
     min_date = opts[:since] || @user.last_emailed_at || @user.last_seen_at || 1.month.ago
 
-    @site_name = SiteSetting.title
+    @site_name = SiteSetting.email_prefix.presence || SiteSetting.title
 
     @header_color = ColorScheme.hex_for_name('header_background')
     @last_seen_at = short_date(@user.last_seen_at || @user.created_at)

spec/mailers/user_notifications_spec.rb

@@ -77,6 +77,13 @@ describe UserNotifications do
         expect(subject.text_part.body.to_s).to be_present
       end
 
+      it "includes email_prefix in email subject instead of site title" do
+        SiteSetting.email_prefix = "Try Discourse"
+        SiteSetting.title = "Discourse Meta"
+
+        expect(subject.subject).to match(/Try Discourse/)
+        expect(subject.subject).not_to match(/Discourse Meta/)
+      end
     end
   end