To disable desktop alerts please follow the procedure below.
Turn on or off Desktop Alerts
1. On the Tools menu, click Options.
2. On the Preferences tab, click E-mail Options, and then click Advanced E-mail Options.
3. Under When new items arrive in my Inbox, clear the Display a New Mail Desktop Alert (default Inbox only) check box.
4. To resume displaying Desktop Alerts, select the Display a New Mail Desktop Alert (default Inbox only) check box.
