4.1.2 Email Bounce Error
Reason
Domain Name Of Email Address Not Valid: Delayed Message
Because the recipient’s email provider says that the recipient’s email address does not exist or unable receive email, the email message has not yet been delivered
How to fix?
Check the recipient’s domain name in the recipient’s email address for misspellings or missing letters. If an error is found, correct it in contacts list or address book for next time.
If necessary, contact the recipient another way to confirm their email address.
4.1.2 – 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.1.2
The destination system specified in the address does not exist or is incapable of accepting mail. For Internet mail names, this means the address portion to the right of the "@" is invalid for mail. This code is only useful for permanent failures.
5.1.2 Email Bounce Error
Reason
Domain Name Of Email Address Not Valid: Message Not Delivered
The message could not be delivered because the recipient’s email provider says that the recipient’s email address does not exist or cannot receive email.
How to fix?
Check the recipient’s domain name in the recipient’s email address for misspellings or missing letters. If an error is found, correct it in contacts list or address book for next time.
It is possible that the domain is temporarily inactive. If the spelling looks correct, contact provider and if necessary, contact the recipient another way.
5.1.2 – 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.1.2
The destination system specified in the address does not exist or is incapable of accepting mail. For Internet mail names, this means the address portion to the right of the "@" is invalid for mail. This code is only useful for permanent failures.
