Free private delivery tool
Understand what each delivery report says.
Turn a delivery failure notification or DSN into structured SMTP evidence. MailDNS separates the reported action from the status family and never treats supplied text as proof of a remote event.
Local by design
The complete bounce stays in this browser tab and is never uploaded.
Per-recipient evidence
Read Final-Recipient, Action, Status, Remote-MTA, and Diagnostic-Code together.
Honest interpretation
Standard status families are explained without inventing provider-specific intent.
Open a bounce notification
Paste the complete delivery failure or choose an .eml/.txt file. Parsing runs in this tab; MailDNS does not upload, store, resolve, or contact anything in the message.
Maximum 5 MB. Addresses and diagnostic text remain on this device.