diff --git a/app/mailers/user_notifications.rb b/app/mailers/user_notifications.rb
index 07b4a0a5dda..bf39562d4d7 100644
--- a/app/mailers/user_notifications.rb
+++ b/app/mailers/user_notifications.rb
@@ -63,15 +63,25 @@ class UserNotifications < ActionMailer::Base
     @post = opts[:post]
     return unless @post.present?
 
+    username = @notification.data_hash[:display_username]
     notification_type = Notification.InvertedTypes[opts[:notification].notification_type].to_s
-    build_email user.email,
-                "user_notifications.user_#{notification_type}",
-                topic_title: @notification.data_hash[:topic_title],
-                message: @post.raw,
-                url: @post.url,
-                username: @notification.data_hash[:display_username],
-                add_unsubscribe_link: true
+
+    email_opts = {
+      topic_title: @notification.data_hash[:topic_title],
+      message: @post.raw,
+      url: @post.url,
+      username: username,
+      add_unsubscribe_link: true
+    }
+
+    # If we have a display name, change the from address
+    if username.present?
+      email_opts[:from] = "\"#{username} @ #{SiteSetting.title}\" <#{SiteSetting.notification_email}>"
+    end
+
+    email = build_email user.email, "user_notifications.user_#{notification_type}", email_opts
   end
+
   alias :user_invited_to_private_message :notification_template
   alias :user_replied :notification_template
   alias :user_quoted :notification_template
diff --git a/lib/email_builder.rb b/lib/email_builder.rb
index c2909f1f676..5f636eb2da7 100644
--- a/lib/email_builder.rb
+++ b/lib/email_builder.rb
@@ -14,7 +14,14 @@ module EmailBuilder
       body << I18n.t("unsubscribe_link", params)
     end
 
-    mail to: to, subject: I18n.t("#{email_key}.subject_template", params), body: body
+    mail_args = {
+      to: to,
+      subject: I18n.t("#{email_key}.subject_template", params),
+      body: body
+    }
+    mail_args[:from] = params[:from] if params[:from].present?
+
+    mail(mail_args)
   end
 
 end
diff --git a/lib/topic_query.rb b/lib/topic_query.rb
index e2802f5cef0..8f2280ba1ca 100644
--- a/lib/topic_query.rb
+++ b/lib/topic_query.rb
@@ -157,9 +157,13 @@ class TopicQuery
       results = default_list(unordered: true, per_page: count)
                  .where('topics.id NOT IN (?)', exclude_topic_ids)
                  .where(closed: false, archived: false, visible: true)
-                 .order('RANDOM()')
 
-      results = results.where('category_id = ?', topic.category_id) if topic.category_id.present?
+      if topic.category_id.present?
+        results = results.order("CASE WHEN topics.category_id = #{topic.category_id.to_i} THEN 0 ELSE 1 END, RANDOM()")
+      else
+        results = results.order("RANDOM()")
+      end
+
       results
     end
 
diff --git a/spec/mailers/user_notifications_spec.rb b/spec/mailers/user_notifications_spec.rb
index c7431c163d8..984c21118e3 100644
--- a/spec/mailers/user_notifications_spec.rb
+++ b/spec/mailers/user_notifications_spec.rb
@@ -44,8 +44,10 @@ describe UserNotifications do
   describe '.user_mentioned' do
 
     let(:post) { Fabricate(:post, user: user) }
+    let(:username) { "walterwhite"}
+
     let(:notification) do
-      Fabricate(:notification, user: user, topic: post.topic, post_number: post.post_number )
+      Fabricate(:notification, user: user, topic: post.topic, post_number: post.post_number, data: {display_username: username}.to_json )
     end
 
     subject { UserNotifications.user_mentioned(user, notification: notification, post: notification.post) }
@@ -53,6 +55,12 @@ describe UserNotifications do
     its(:to) { should == [user.email] }
     its(:subject) { should be_present }
     its(:from) { should == [SiteSetting.notification_email] }
+
+    it "should have the correct from address" do
+      subject.header['from'].to_s.should == "\"#{username} @ #{SiteSetting.title}\" <#{SiteSetting.notification_email}>"
+    end
+
+
     its(:body) { should be_present }
   end