Enhanced status code

SMTP error X.7.10

Encryption needed

Updated Jul 1, 2026

The short answer

Encryption needed Common cause: AUTH method requires a secure transport layer

Quick fix

Enable TLS before authenticating

This code is written X.7.10 because the reason is the same whether the failure is temporary (a 4 first digit) or permanent (a 5). Read the first digit of your own bounce to know which applies.

How to fix it

Enable TLS before authenticating

Related codes

X.7.0 Other or undefined security status X.7.1 Delivery not authorized X.7.2 Mailing list expansion prohibited X.7.3 Security conversion required but impossible X.7.4 Security features not supported X.7.5 Cryptographic failure
All SMTP error codes
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