Change Windows Mail security settings
You can use the Security tab in the Windows Mail Options dialog box to change settings for virus protection and secure e‑mail. To access the Security tab:
Open Windows Mail by clicking the Start button , clicking All Programs, and then clicking Windows Mail.
Click the Tools menu, click Options, and then click the Security tab.
Under Download Images, select the Block images and other external content in HTML e‑mail check box to prevent Windows Mail from downloading images that can make your identity known to junk e‑mail senders. For more information, see View images that Windows Mail blocked.
Under Secure Mail, you'll find options for signing e‑mails with digital signatures that verify your identity, and encrypting e‑mails to keep people other than your intended recipients from reading them. For details on changing these settings, see Use digital IDs to sign or encrypt Windows Mail messages.