postsuper -h <queue-id> postsuper -h ALLMessages on hold show up with an exclamation mark (!) in the mailq Release mail from being on hold:
postsuper -H <queue-id> postsuper -H ALL
Computer Tips - Postfix: put mail on hold
Date: 2010apr21
Product: postfix
Q. Postfix: put mail on hold
A.
Put some mail on hold: