Follow these basic guidelines when dealing with attachments in an e-mail message, no matter what e-mail program you're using:
1. Don't open any attachment unless you know whom it's from and you were expecting it.
2. If you receive an e-mail message with an attachment from someone you don't know, delete it immediately.
3. Use antivirus software and keep it updated.
4. If you need to send an e-mail attachment to someone, let them know you'll be sending it so they don't think it's a virus.
5. Use spam filters to help block unwanted e-mail, much of which contains dangerous attachments. For information on how to do this with Outlook, see Update junk e-mail filters for Outlook.