Enhanced status code Success

SMTP error X.2.2

Mailbox full

Updated Jul 1, 2026

The short answer

Mailbox full Common cause: Recipient exceeded mailbox quota

Quick fix

Retry later or ask the recipient to free space

2 - Success. Not an error - the server accepted or completed the action.
This code is written X.2.2 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

Retry later or ask the recipient to free space

Related codes

X.2.0 Other or undefined mailbox status X.2.1 Mailbox disabled X.2.3 Message length exceeds mailbox limit X.2.4 Mailing list expansion problem
All SMTP error codes
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