4.7.3 Email Bounce Error
Reason
Security conversion required but not possible: Delayed Message
The email message has not yet been delivered because the recipient’s email program and the sender’s email program had issues with the security protocols between them.
How to fix?
Retry the email message see if it was a one-time problem or if the same error occurs. Otherwise, contact the support team as the email system may have a security issue. This is not typically something that you can fix.
4.7.3- 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.7.3
The sender is not authorised to send a message to the intended mailing list. This is useful only as a permanent error.
5.7.3 Email Bounce Error
Reason
Security conversion required but not possible: Message Not Delivered
The message could not be delivered because the recipient’s email program and the sender’s email program had issues with the security protocols between them.
How to fix?
Retry the email message see if it was a one-time problem or if the same error occurs. Otherwise, contact the support team as the email system may have a security issue. This is not typically something that you can fix.
5.7.3- 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.7.3
The sender is not authorised to send a message to the intended mailing list. This is useful only as a permanent error.