attempt to fix the UTF-8 warn in the log, turns out this runs really deep, when you hit deliver in test it clones the mail not setting charset properly, leaving as is for today but fixing prod at least

lib/email_builder.rb

@@ -20,6 +20,7 @@ module EmailBuilder
       body: body
     }
     mail_args[:from] = params[:from] || SiteSetting.notification_email
+    mail_args[:charset] = 'UTF-8'
     mail(mail_args)
   end
 

lib/email_sender.rb

@@ -19,7 +19,8 @@ class EmailSender
     return if @message.to.blank?
     return if @message.body.blank?
 
-    plain_body = @message.body.to_s
+    @message.charset = 'UTF-8'
+    plain_body = @message.body.to_s.force_encoding('UTF-8')
 
     @message.html_part = Mail::Part.new do
       content_type 'text/html; charset=UTF-8'

spec/components/system_message_spec.rb

@@ -13,22 +13,12 @@ describe SystemMessage do
     let(:post) { system_message.create(:welcome_invite) }
     let(:topic) { post.topic }
 
-    it 'should create a post' do
+    it 'should create a post correctly' do
       post.should be_present
-    end
-
-    it 'should be a private message' do
       topic.should be_private_message
-    end
-
-    it 'should have the correct topic subtype' do
       topic.subtype.should == TopicSubtype.system_message
-    end
-
-    it 'should be visible by the user' do
       topic.allowed_users.include?(user).should be_true
     end
-
   end
 
   context '#system_user' do