use the "official" pexp, from antoine@

src/etc/rc.d/sendmail

@@ -1,12 +1,12 @@
 #!/bin/sh
 #
-# $OpenBSD: sendmail,v 1.2 2011/07/07 05:00:19 robert Exp $
+# $OpenBSD: sendmail,v 1.3 2011/07/07 05:15:45 robert Exp $
 
 daemon="/usr/sbin/sendmail"
 
 . /etc/rc.d/rc.subr
 
-pexp="(sendmail: accepting.*|${daemon} ${daemon_flags})"
+pexp="(sendmail: accepting.*|${daemon}${daemon_flags:+ ${daemon_flags}})"
 
 rc_bg=YES