Fix "552 5.2.2": The recipient's mailbox is full

If your email is bouncing with 552 5.2.2, it means the recipient's mailbox is full. Here is exactly what causes it and how to fix it.

What 552 5.2.2 means

552 5.2.2 is a soft, recipient-side problem: their mailbox is over quota. It often clears on its own, but persistent full mailboxes should eventually be suppressed.

How to fix 552 5.2.2

• Retry for a few days, then suppress if it never clears.
• Do not treat a single 5.2.2 as a hard bounce.
• Monitor addresses that are chronically full.

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