Gmail 452 4.2.2: recipient's inbox is full

Gmail 452 4.2.2 is a temporary refusal: the recipient’s inbox has no storage space left. The address exists, so ReputeCast keeps it and tries again on the next send. If the same address keeps coming back full, it is probably no longer read, and you can decide to stop mailing it.

What Gmail means

The recipient’s inbox is out of storage space. Please direct the recipient to Manage files in your Google Drive storage.

Gmail has a permanent version for an inbox that is also inactive:

552 5.2.2 The recipient’s inbox is out of storage space and inactive.

Source: Gmail SMTP errors and codes, Google Workspace Help. Checked October 2026.

Why it happens

The recipient has used all the storage of their Google account, which Gmail’s message points to with its link to Google Drive storage. Nothing about your mail causes it. An inbox that stays full for weeks usually belongs to someone who stopped using it.

How ReputeCast classifies it

• Bounce class: mailbox_full, from the enhanced status code 4.2.2 (5.2.2 gets the same class).
• While the sending provider retries, each attempt is a deferral in the event log.
• When the sending provider gives up, the bounce is a soft bounce in the report row Soft · mailbox full, with Retry next send in the Suppression column. The address isn’t suppressed, and the report doesn’t offer to suppress it.
• On the Transactional stream, a third soft bounce within 7 days suppresses the address.
• For 552 5.2.2, the class is the same, but a sending provider that reports it as a permanent bounce makes it a hard bounce, which suppresses the address.

Before you begin

• reports:view to read the campaign report.
• subscribers:edit to add an address to the suppression list by hand.

Decide what to do with full inboxes

1. Open Campaigns and the campaign’s Report. The Soft · mailbox full row shows how many addresses were full.
2. Leave them for now. One full inbox is temporary, and ReputeCast sends to the address again next time.
3. Watch engagement. Contacts who stop opening move through the list health tiers, and the sunset policy, on in new workspaces, stops Broadcasts to contacts who stay inactive.
4. To stop mailing an address that stays full, add it in Audience › , then Suppression list with Add address.

Check that it worked

• Addresses you added appear in the suppression list, and later campaigns skip them.
• The Soft · mailbox full row of later campaigns stays small.

Troubleshooting

• The same addresses are full on every send. Treat them as inactive: suppress them, or let the sunset policy stop Broadcasts to them.
• A full-mailbox address was suppressed. It came back as 552 5.2.2 or as a Transactional soft bounce for the third time in 7 days. See when ReputeCast suppresses an address.

Related

• SMTP error codes
• Gmail 550 5.1.1, an account that doesn’t exist
• The suppression list
• Read campaign reports