Definition
TLS encrypts mail in transit between servers. Certificates identify the server and enable the encryption.
Best Practices
- Keep certificates valid and renewed before expiry.
- Pin to strong CAs and current protocols.
- Watch for downgrade attempts on transport.
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Related Glossary Terms
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Email Authentication Protocols
Email authentication protocols are technical standards that verify the identity of an email sender, helping mailbox providers distinguish legitimate mail from spam and phishing.
BIMI
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Bounce Classification
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Frequently Asked Questions
To encrypt SMTP transport and prove server identity.
Yes, but insecure; modern servers prefer TLS.
TLS used if both sides agree, not enforced.