452 4.2.2 Mailbox full
Sample bounce line
452 4.2.2 <[email protected]>: Mailbox full
What it means
RFC 3463 defines X.2.2 as Mailbox full: the user has exceeded a per-mailbox administrative quota or physical capacity, and the recipient can delete messages to make space. RFC 3463 says this code should be used as a persistent transient failure, so the delivery is delayed and retried rather than permanently refused.
Why it happens
- The recipient exceeded a per-mailbox quota or the mailbox reached its physical size limit
- Dovecot: the quota plugin rejects delivery; its default message is 'Quota exceeded (mailbox for user is full)'
- Postfix local(8): mailbox_size_limit (default 51200000) is the maximal size of any local individual mailbox or maildir file
How to fix it
- Recipient: delete or archive messages to free space, or ask the administrator for a larger quota
- Sender: retry later or contact the recipient by another route
- Admin: raise the quota (Dovecot quota settings) or mailbox_size_limit (Postfix local delivery); Dovecot's quota_exceeded_message text can be customized
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