In the sendmail start script (/etc/init.d/sendmail) sendmail and the sendmail client should get started.
But for some reasons the client never starts.
This seems to be a problem with startproc. If i remove startproc the client starts correctly:

    start)
        echo -n "Initializing SMTP port (sendmail)"
        startproc -p $srvpid -i $msppid /usr/sbin/sendmail $SENDMAIL_ARGS
        rc_status
        poll25
        rc_status
# [UH]  startproc -p $msppid -i $srvpid /usr/sbin/sendmail $SENDMAIL_CLIENT_ARGS
        /usr/sbin/sendmail $SENDMAIL_CLIENT_ARGS
        rc_status -v

This is no real solution, but startproc seems to ignore the -i option ...