If you use an Exchange email account for work, for example, you'll find a designated area for security settings where you can clearly see whether encryption/security is enabled for the incoming and outgoing connections and for your Exchange account. If it isn't enabled, check with your email provider to see whether the provider supports encryption, and consider switching to a service that allows SSL/TLS encryption.
You can and should encrypt your individual email messages during transit, but both you and your recipient must do some work ahead of time to make the protection work properly. You can use encryption features built into your email service, or you can download encryption software or client add-ons (such as those that use ). In a pinch, you can use a Web-based encryption email service like or , though doing so forces you to trust a third-party company.
Most forms of message encryption, including S/MIME (Secure/Multipurpose Internet Mail Extensions) and OpenPGP, require you to install a security certificate on your computer and to give your contacts a string of characters called your public key before they can send you an encrypted message. Likewise, the intended recipients of your encrypted message must install a security certificate on their computer and give you their public key in advance.
Support for the S/MIME standard is built into many email clients, including Microsoft Outlook. In addition, Web browser add-ons, like for Firefox, support Web-based email providers as well. To get started, you can apply for a security certificate from a company such as .