Postfix - e-mails of some domains are in queue

Hi guys,

i have a problem with the delivery of the e-mails to the mail accounts. e-mails of some domains hang in the queue of plesk. when i call "mailq" on the server, there ist this message:

A6BB44140D3A 1307 Thu May 28 05:33:51 root@binaerhosting.de
(temporary failure. Command output: /bin/sh: 1: /usr/bin/deliverquota: not found 4.2.1 Message can not be del
ivered at this time)
ewert@binaerix.de

plesk is in the original version, so i don't switched from...

Postfix - e-mails of some domains are in queue