How to repeat delay_warning_time messages ?

3 msg	Server configuration Error
1 msg	relay_transport
1 msg	Catch-all mailbox
4 msg	Trouble with HTC S710 device and SMTPS
3 msg	psotfix server TLS failed
3 msg	failed-delivery message notifications setup
2 msg	proxy_interfaces understanding
1 msg	warning: transport virtual failure
2 msg	how to relay for most recipients and forward fo...
2 msg	Rewriting outbound addresses
2 msg	virtual mailboxes/domains and aliases
3 msg	Enforced TLS Success?
1 msg	Postfix 2.5 RC2 and snapshot release
11 msg	Problem with Postfix and LDAP (SSL / TLS)
4 msg	More on Enforced TLS
3 msg	delivery reciept

How to repeat delay_warning_time messages ?
\ Alexander Grüner (16 Jan 2008)
. \ Ralf Hildebrandt (16 Jan 2008)
. . \ (Wietse Venema) (16 Jan 2008)
. . . \ Alexander Grüner (17 Jan 2008)

2 msg	sender notification
5 msg	Using 'nolisting' to reduce spam
1 msg	mail priority by sender

Subject:	How to repeat delay_warning_time messages ?
Group:	Postfix-users
From:	Alexander Grüner
Date:	16 Jan 2008

Hello,

delay_warning_time = 2h works fine here.

Is it possible to repeat this warning message every x hours if the mail
is still not delivered ?

Regards,
Alexander