Resolved. Incoming test email is being delivered normally again, after delays that began Oct 12 at about 12:20 PM ET and a full outage on Oct 16 from about 8:15 AM to 12:15 PM ET.

Sending mail servers retry automatically, so most delayed messages arrived late rather than being lost. If a test from Oct 12–16 is still missing a message, please re-send it.

What we changed: the mail server now accepts mail for our test domain only, the spam has been removed, and an automatic delivery check now runs every 5 minutes and feeds this page.

The spam has been removed and storage freed, and new test email is being stored again. We're watching delivery.

Cause identified: spam addressed to other domains has filled the mail server's storage limit. We're blocking mail for other domains and removing the spam now.

Incoming test email stopped arriving entirely. The mail server's storage was now completely full, so every new message was turned away.

Incoming test email began arriving late, sometimes by several hours. Spam addressed to other domains overloaded the mail server, so it accepted test email slowly or not at all, and the sending mail server retried later. The Inbox app itself stayed available.