Definition
SMTP TLS 1.3 refers to the use of TLS 1.3, the latest Transport Layer Security version, to encrypt SMTP email traffic in transit between mail servers. TLS prevents messages and credentials from being read or tampered with during delivery.
TLS 1.3 improves on earlier versions with faster, stronger handshakes and better encryption, making in-transit email more secure. Email connections support a range of TLS versions; the strongest possible connection is negotiated when both ends support it.
While you usually do not configure TLS directly, mail providers manage it. When evaluating providers or infrastructure, favor those supporting modern TLS like 1.2 and 1.3, since older versions are deprecated and increasingly blocked.
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Frequently Asked Questions
TLS is encryption for email in transit between servers. SMTP TLS encrypts mail connections so messages cannot be read or altered during delivery.
TLS 1.3 brings faster and stronger handshakes with modern encryption, improving both the security and performance of encrypted email transmission.
Usually your email provider or infrastructure manages it. Just ensure your sending infrastructure supports modern TLS versions rather than deprecated ones.