Is there a way to requeue bounced mails in Postfix?

We have a postfix server which delivery via a smarthost / relay. Due to a misconfiguration we 60 emails were bounced back.

Nov 25 07:48:06 example postfix/smtp[2632]: F3F1F1A82421: to=<[email protected]>, relay=mail.example.com[....]:25, delay=0.13, delays=0.01/0/0.09/0.03, dsn=5.0.0, status=bounced (host mail.example.com[....] said: 550 Relay not 

Is there a way to requeue these mails or are they "lost" and have to be regenerated by the mail sender?

No. While the error is temporary, postfix will retry to send the mail in regular intervals.

But with a final error like this the process is finished. The mail will have to be sent again.