Use spam filtering technology. For more information, see Help keep spam out of your inbox.

Don't make investment decisions based on anonymous e-mail or text messages you receive.

Don't open attachments in unsolicited e-mails. To avoid being caught by spam filters, stock spam usually is sent as an image or as a PDF attachment.

Use an Internet service provider (ISP) or e-mail provider that has implemented Sender ID Framework, a technical solution to detect and block spoofed e-mail. Windows Live Hotmail and Exchange Server 2003/2007 are two solutions that support this technology.