diff --git a/etc/mail/sendmail.cf.additions b/etc/mail/sendmail.cf.additions
index 0921b96cc21b..42305a8656b4 100644
--- a/etc/mail/sendmail.cf.additions
+++ b/etc/mail/sendmail.cf.additions
@@ -100,15 +100,23 @@ R$+.REJECT		$#error $@ 5.2.1 $: 550 $1
 R<$*> $*		$: $1
 # mail must NOT be addressed "fakenames"--END
 # mail must come from or go to this machine or machines we allow to relay--BEGIN
-# R$*			$: $>Parse0 $>3 $1
-# R$+ < @ $* . > $*	$: $1 < @ $2 >
-# R$+ < @ $=w>		$@ OK
-# R$+ < @ $* $=R>	$@ OK
-# R$*			$: $(dequote "" $&{client_name} $)
-# R$=w			$@ OK
-# R$* $=R			$@ OK
-# R$@			$@ OK
-# R$*			$#error $@ 5.7.1 $: "550 Relaying Denied"
+# from http://www.informatik.uni-kiel.de/%7Eca/email/check.html#check_rcpt
+R$+			$: $(dequote "" $&{client_addr} $) $| $1
+R0 $| $*		$@ ok
+R$={LocalIP}$* $| $*	$@ ok
+# not local, check rcpt
+R$* $| $*		$: $>3 $2
+# remove local part, maybe repeatedly
+R$+			$:$>removelocal $1
+# still something left?
+R$*<@$+>$*		$#error $@ 5.7.1 $: 550 we do not relay
+#
+Sremovelocal
+# remove RelayTo part (maybe repeatedly)
+# R$*<@$*$={RelayTo}.>$*	$>3 $1 $4
+R$*<@$=w.>$*		$: $>removelocal $>3 $1 $3
+R$*<@$*>$*		$@ $1<@$2>$3
+# dequote local part
+R$-			$: $>3 $(dequote $1 $)
+R$*<@$*>$*		$: $>removelocal $1<@$2>$3
 # mail must come from or go to this machine or machines we allow to relay--END
-R$*			$@ OK
-