To set up email in QuickBooks, go to the Edit menu and select Preferences, then choose Send Forms. From there, select your preferred email option—such as QuickBooks Email, Outlook, or Web Mail—and enter the required information like your email address and server settings. Once configured, you can easily email invoices, estimates, and other forms directly from QuickBooks. This setup helps streamline communication with customers and saves time by sending documents without leaving the software.