First, we dislike the idea of computers auto-deleting e-mails without human intervention. Therefore, all e-mail detected as Spam (unsolicited, commercial or "junk" e-mail) are put into a folder called SPAM. E-mails that get sent into the SPAM folder are kept for 1 month and are then auto-deleted to save disk space.
If you access your e-mail via our web-based e-mail system (or via the IMAP protocol) you can subscribe to the SPAM folder (subscribe/unsubscribe functions are under the Folder link).
Thus, if you ever wonder if some legitimate human's e-mail got flagged as spam, you can check this SPAM folder.
We process mail using not one but several spam-checking techniques. These include checking messages against online databases of known spam, greylisting, and Bayesian filtering techniques.