Additional NDR Reference
The following table provides a description of delivery status notification codes. This table can help you interpret the codes that you receive in NDRs.
Delivery status notification codes
Delivery status notification code | Description |
---|---|
X.1.0 |
Other address status |
X.1.1 |
Bad destination mailbox address |
X.1.2 |
Bad destination system address |
X.1.3 |
Bad destination mailbox address syntax |
X.1.4 |
Destination mailbox address ambiguous |
X.1.5 |
Destination mailbox address valid |
X.1.6 |
Mailbox has moved |
X.1.7 |
Bad sender's mailbox address syntax |
X.1.8 |
Bad sender's system address |
X.2.0 |
Other or undefined mailbox status |
X.2.1 |
Mailbox disabled, not accepting messages |
X.2.2 |
Mailbox full |
X.2.3 |
Message length exceeds administrative limit |
X.2.4 |
Mailing list expansion issue |
X.3.0 |
Other or undefined mail system status |
X.3.1 |
Mail system full |
X.3.2 |
System not accepting network messages |
X.3.3 |
System not capable of selected features |
X.3.4 |
Message too big for system |
X.3.5 |
System incorrectly configured |
X.4.0 |
Other or undefined network or routing status |
X.4.1 |
No answer from host |
X.4.2 |
Bad connection |
X.4.3 |
Routing server failure |
X.4.4 |
Unable to route |
X.4.5 |
Network congestion |
X.4.6 |
Routing loop detected |
X.4.7 |
Delivery time expired |
X.5.0 |
Other or undefined protocol status |
X.5.1 |
Invalid command |
X.5.2 |
Syntax error |
X.5.3 |
Too many recipients |
X.5.4 |
Invalid command arguments |
X.5.5 |
Wrong protocol version |
X.6.0 |
Other or undefined media error |
X.6.1 |
Media not supported |
X.6.2 |
Conversion required and prohibited |
X.6.3 |
Conversion required but not supported |
X.6.4 |
Conversion with loss performed |
X.6.5 |
Conversion failed |
X.7.0 |
Other or undefined security status |
X.7.1 |
Delivery not authorized, message refused |
X.7.2 |
Mailing list expansion prohibited |
X.7.3 |
Security conversion required but not possible |
X.7.4 |
Security features not supported |
X.7.5 |
Cryptographic failure |
X.7.6 |
Cryptographic algorithm not supported |
X.7.7 |
Message integrity failure |