SSL should already be available from your mail host, although it's often not required. And for compatibility, many mail clients leave it off by default. Here's how to be sure you're making that secure connection.
In Outlook, pick Tools, Account Settings, and double-click your account name. Click More Settings. Click the Advanced tab, and be sure SSL or TLS are enabled.
If you connect through webmail provided by your host, verify that SSL/TLS security is enabled on that page; and look for "https://" to lead the URL. If using a third-party webmail service, be sure to connect to something you trust. When needed, I use and click the Secure Login option for a private connection.