OutOfOffice mail rejected From:<>

[Samp]

Hi,

I have problem with mail sent from OutOfOffice rejected as spam because sent with empty from field From: <>

see the log:

Nov 16 22:19:43 soleil-xl postfix/cleanup[31734]: 93C1CCC2C3: hold: header Received: from postfix.geismar.com (postfix.geismar.com [88.190.221.41])??by soleil-xl.arial-concept.com
 (Postfix) with ESMTP id 93C1CCC2C3??for <samp@arial-concept.com>; Tue, 16 Nov 2010 22:19:43 +01 from postfix.geismar.com[88.190.221.41]; from=<> to=<samp@arial-concept.com> proto
=ESMTP helo=<postfix.geismar.com>
Nov 16 22:19:43 soleil-xl MailScanner[19992]: Message 93C1CCC2C3.6B78E from 88.190.221.41 has no (or invalid) watermark or sender address
Nov 16 22:19:43 soleil-xl MailScanner[19992]: Spam Checks: Found 1 spam messages
Nov 16 22:19:43 soleil-xl MailScanner[19992]: Non-delivery of spam: message 93C1CCC2C3.6B78E from  to samp@arial-concept.com with subject Re: Message de test 4
Nov 16 22:19:43 soleil-xl MailScanner[19992]: Spam Actions: message 93C1CCC2C3.6B78E actions are store

How to fix it ?

Sam.