Enhanced status code

SMTP error X.7.17

Mailbox owner has changed

Updated Jul 1, 2026

The short answer

Mailbox owner has changed Common cause: Recipient mailbox changed ownership after the specified RRVS date

Quick fix

Verify the intended recipient before resending

This code is written X.7.17 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

Verify the intended recipient before resending

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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