A postfix server of mine was for a short period of time on a blacklist (misconfigured HELO String 'localhost.localdomain').
The 550 rejected emails got deleted immediately from the postfix queue, which I don't want. This is a low traffic server just for some outgoing web server mails.
To don't let this happen again and lose some mails, I set "soft_bounce = yes". I wrote a script that checks the mail queue periodically and sends a status email, so that I can do something with the bounced mails.
To differentiate the hard bounced from the soft bounced emails I would like to put the hard bounced mails directly to the hold queue.
Q: How can I put hard bounced email to the hold queue, instead to remove the email?