--- ifup-post.orig	Wed Mar 21 12:54:36 2001
+++ ifup-post	Fri Apr 20 01:35:29 2001
@@ -32,7 +32,8 @@
 	[ "$?" = 0 ] && set_hostname $HOSTNAME
 fi
 
-if [ "$PEERDNS" != no -o -n "$RESOLV_MODS" -a "$RESOLV_MODS" != no ]; then
+if [ -n "$PEERDNS" -a "$PEERDNS" != no -o \
+     -n "$RESOLV_MODS" -a "$RESOLV_MODS" != no ]; then
   [ -n "$MS_DNS1" ] && DNS1=$MS_DNS1
   [ -n "$MS_DNS2" ] && DNS2=$MS_DNS2
   if [ -n "$DNS1" ] && ! grep -qs "^nameserver $DNS1" /etc/resolv.conf &&
@@ -93,7 +94,22 @@
 # Notify programs that have requested notification
 do_netreport
 
-IFDOWN_LOCAL=/sbin/ifup-local
+POSTFIX=/usr/sbin/postfix
+if [ -n "$SMTP_RELAYHOST" -a -x "$POSTFIX" ] && tr=`mktemp /tmp/postfix.XXXXXX`
+then
+    grep -v ^relayhost /etc/postfix/main.cf >$tr
+    echo "relayhost = $SMTP_RELAYHOST" >>$tr
+
+    # backup main.cf
+    cp -af /etc/postfix/main.cf /etc/postfix/main.cf.save
+
+    cat $tr > /etc/postfix/main.cf
+    rm -f $tr
+
+    "$POSTFIX" reload 
+fi
+
+IFUP_LOCAL=/sbin/ifup-local
 if [ -x "$IFUP_LOCAL" ]; then
     "$IFUP_LOCAL" "$DEVICE"
 fi