Use SSL With an Email Account in Apple Mail
Unless you use encryption, email messages travel around the world in plain text, meaning anyone who intercepts them can read their contents. There is a way to at least partially secure the connection from you to your mail server. Here’s how to enable SSL encryption for an email account in macOS Mail: SSL can slightly reduce performance because all communication with the server will be encrypted. You may or may not notice a change in speed depending on how modern your Mac is and what kind of bandwidth you have to your email provider.
SSL vs. Encrypted Email
SSL encrypts the connection between your Mac and your email provider’s server. This approach offers some degree of protection from people on your local network, as well as your ISP, from snooping on your email transmissions. However, SSL does not encrypt email messages; it only encrypts the communications channel between Apple Mail and your email provider’s server. As such, the message is still unencrypted when it moves from your provider’s server to its final destination. To fully protect the contents of your email from origin to destination, you will have to encrypt the message itself using an open-source technology like GPG or through the use of a third-party encryption certificate. Alternatively, make use of a free or paid secure email service, which not only encrypts your messages but also protects your privacy.
