S3 stands for 'SpamStopper Stopper', a tool that prevents spam crawlers from collecting email addresses from websites. Spam crawlers are similar to Google crawlers, but they only collect a few pieces of information, particularly anything with '@' in it. To protect against these crawlers, S3 uses numeric escapes and image files that they cannot read.
Mia for Gmail (was Notifier Pro for Gmail) is a desktop Gmail client which sits politely in your menu bar.
