4.1.0 Email Bounce Error
Reason
Unknown Issue With Recipient’s Email Address: Delayed Message
The email message has not yet been delivered because there is a problem of some sort with the recipient’s email address.
How to fix?
You’ll need to check misspellings or missing letters in your recipient’s email address, correct it if you find an error. Alternatively, contact your recipient in another way to confirm their email address.
4.1.0 – Official definition from ITEF
For the code that starts from 4.X.X
A persistent transient failure is one in which the message as sent is valid, but persistence of some temporary condition has caused abandonment or delay of attempts to send the message. If this code accompanies a delivery failure report, sending in the future may be successful.
For the code that starts from X.1.0
Something about the address specified in the message caused this DSN.
5.1.0 Email Bounce Error
Reason
Unknown Issue With Email Address: Message Not Delivered
The message could not be delivered because there is a problem of some sort with the recipient’s email address.
How to fix?
You’ll need to check misspellings or missing letters in your recipient’s email address, correct it if you find an error. Alternatively, contact your recipient in another way to confirm their email address.
5.1.0 – Official definition from ITEF
For the code that starts from 5.X.X
A permanent failure is one which is not likely to be resolved by resending the message in the current form. Some change to the message or the destination must be made for successful delivery.
For the code that starts from X.1.0
Something about the address specified in the message caused this DSN.
