Enhanced status code

SMTP error X.6.0

Other or undefined media error

Updated Jul 1, 2026

The short answer

Other or undefined media error Common cause: Message content caused an unspecified delivery problem

Quick fix

Inspect content format and full bounce response

This code is written X.6.0 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

Inspect content format and full bounce response

Related codes

X.6.1 Media not supported X.6.2 Conversion required and prohibited X.6.3 Conversion required but unsupported X.6.4 Conversion with loss performed X.6.5 Conversion failed X.6.6 Message content not available
All SMTP error codes
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