Only mark a message as read after we have validated the email reply

script/deliver-message

@@ -14,12 +14,12 @@ else
   digest = message.digest
   from = message.recipient
   to = message.sender
-
-  message.update_attribute(:message_read, true)
 end
 
 exit 0 unless recipient[3] == digest[0,6]
 
+message.update_attribute(:message_read, true) if message
+
 mail = Mail.new(STDIN.readlines.join)
 
 if mail.multipart?