4.0.0 Email Bounce Error

Reason

Unknown issue: Delayed Message

Because of an unknown issue the email message could not be delivered.

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.

4.0.0 – 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.0.0

Other undefined status is the only undefined error code. It should be used for all errors for which only the class of the error is known.

5.0.0 Email Bounce Error

Reason

Unknown issue: Message Not Delivered

Because of an unknown issue the email message could not be delivered.

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.

5.0.0 – 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.0.0

Other undefined status is the only undefined error code. It should be used for all errors for which only the class of the error is known.