SMTP TLS encryption is popular because it provides adequate data protection without creating a complicated user experience for email recipients. Sometimes, though, the experience is too seamless, and recipients may wonder if the message was protected at all.
Luckily, there is a way to tell if an email was encrypted using TLS. To see if a message was sent securely, we can look at the raw headers of the email. However, it requires some knowledge and experience to understand the text. It is actually easier to tell if a recipient’s server supports TLS than to tell if a particular message was securely transmitted.
To analyze a message for transmission security, we will look at an example email message sent from Hotmail to LuxSci. We will explain what to look for when decoding the message headers and how to tell if the email was transmitted using TLS encryption.
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