pigeonhole / vacation

[A. Schulze]

Hello,

we use the sieve vacation module to answer messages for certain mailboxes.
vacation send back answers to most but not all messages wich is fine  
and intended.

.dovecot.sieve looks like this:

   require ["vacation", "variables"];

   if header :matches "subject" "*" {
     vacation :subject "Automatic response to: ${1}" "thanks for your message";
     keep;
   }


But now I would like to distinct messages that where answered from  
those where the vacation module
did not send back a message. Is it possible to store answered messages  
in one folder and unanswered in an other?

   # probably invalid sieve syntax
   if vacation .... {
     fileinto "answered/";
     stop;
   else
     fileinto "unanswered/";
     stop;
   }

After reading RFC 5230 I feel it's not possible at all :-/

Andreas