Web Wiz NewsPad does not actually send the emails to their final destination it simply sends the emails to your SMTP server which sends the emails to their
destination.
It would be your SMTP server that sends you the delayed message and the final failed message. This has nothing to do with NewsPad so would not matter which email component that you use to send the email to the SMTP server.
You need to contact who ever runs your SMTP server and let them know there is an issue with the mail server relaying emails.