[Exim] acl trouble with custom log entries

Hello list,

I still have son trouble in understanding the correct acl behaviour.

I have a line

  # Reject virus infected messages.
  deny  message = This message contains malware ($malware_name)
        malware = *

And I want to log to my main log a custiomized entry ONLY if
a virus was found. So I put a

  # Reject virus infected messages.
  warn condition =  ${if def:malware_name}{1}{0}
       logwrite = ## acl_check_content malware ($malware_name)
       malware = *

but I got following error:

2004-01-29 17:07:58 1AmEhy-00038g-GT H=mail.myhost.de (mail.myhost.de)
[XX.XX.XX.XX] F=<tom@???> temporarily rejected after DATA: failed to expand
ACL string "${if def:malware_name}{1}{0}": missing or misplaced { or }


Thanks for your help in advance.

Thomas.
--
Thomas Baumann // tirili+list.exim@???

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