Microsoft finally seems ready to enforce a long-needed policy for its Hotmail Web-based email system: Use your account or forfeit it. The company is giving Hotmail users a 30-day sign-on limit. If a user goes 30 days without accessing his or her account, Microsoft will drop the account and delete all related messages, attachments, and contacts. Microsoft says that it's instituting the policy change to relieve server load and improve performance. (A similar 45-day policy was already in place but was apparently ineffective.) The net result is bound to be a sharp drop in the number of Hotmail accounts; surely many of the countless existing Hotmail user accounts are inactive.