Permanent (5xx)
552 5.2.2
Mailbox full (permanent)
The recipient's mailbox has been over quota long enough that the receiving server has stopped accepting more mail for it at all.
552 5.2.2 Mailbox full
What it means in practice
The mailbox has been full long enough that the receiving server now rejects new mail permanently. Compare 452 4.2.2, the temporary version of the same condition.
Some providers send 552 5.2.2 on the first over-quota attempt rather than after a grace period, so a single one isn't proof the mailbox is dead. A sensible rule for transactional mail: suppress the address after two or three 5.2.2 bounces across separate sends, and ask the user to update their email address the next time they sign in.
Common causes
- Abandoned or inactive recipient mailbox.
What to do
- →Suppress after repeated occurrences for the same address - a mailbox this full for this long is unlikely to ever accept mail again.