[Dovecot] Sieve notify messages

Hi All

I'm using dovecot 2.0.16 with the pigeonhole plugin 0.25.

I'm trying to use the notifiy mechanism from sieve to send notifications when a mail arrives in the mailbox. The message is checked to be a 8bit message, otherwise it is replaced by the default message "Notification of new message." How can I create a 8bit message body within the sieve script that is accepted by the notification process?

e.g. notify :message "Subject: ${subject}" "mailto:email@domain.com";

Do I have to put the message body into the :message string? Or how can I define a custom message body that is accepted by notify?

Best regards Andreas