4.4.0 Email Bounce Error
Reason
Unknown Issue With Network Connection: Delayed Message
The email message has not yet been delivered because of an unknown network connection problem between the email providers.
How to fix?
Contact the sender’s email or network support team as there was a network issue, possibly with the sender’s email server. This is typically something that needs help-desk support to resolve.
4.4.0 – 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.4.0
Something went wrong with the networking, but it is not clear what the problem is, or the problem cannot be well expressed with any of the other provided detail codes.
5.4.0 Email Bounce Error
Reason
Unknown Issue With Network Connection: Message Not Delivered
The message could not be delivered because of an unknown network connection problem between the email providers.
How to fix?
Contact the sender’s email or network support team as there was a network issue, possibly with the sender’s email server. This is typically something that needs help-desk support to resolve.
5.4.0- 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.4.0
Something went wrong with the networking, but it is not clear what the problem is, or the problem cannot be well expressed with any of the other provided detail codes.
