diff --git a/src/lib-sieve/plugins/subaddress/ext-subaddress.c b/src/lib-sieve/plugins/subaddress/ext-subaddress.c
index 1d85469f7873ab9fd40931ac890853aeb50d18ec..01f1c892f86b7b4cf7a35b80c99f8e53e768f8f3 100644
--- a/src/lib-sieve/plugins/subaddress/ext-subaddress.c
+++ b/src/lib-sieve/plugins/subaddress/ext-subaddress.c
@@ -119,8 +119,6 @@ static const char *subaddress_user_extract_from
 {
 	const char *sep;
 
-	if ( address->local_part == NULL ) return NULL;
-
 	sep = strstr(address->local_part, sieve_subaddress_sep);
 	
 	if ( sep == NULL ) return address->local_part;
@@ -133,8 +131,6 @@ static const char *subaddress_detail_extract_from
 {
 	const char *sep;
 
-	if ( address->local_part == NULL ) return NULL;
-
 	if ( (sep=strstr(address->local_part, sieve_subaddress_sep)) == NULL )
 		return NULL; 
 
diff --git a/src/lib-sieve/sieve-address-parts.c b/src/lib-sieve/sieve-address-parts.c
index 208b0f81457658cd55192bcb0dbef0a2e2541510..064c358de139dde112d0b7942a0b9b3793e817c6 100644
--- a/src/lib-sieve/sieve-address-parts.c
+++ b/src/lib-sieve/sieve-address-parts.c
@@ -242,14 +242,15 @@ int sieve_address_match
 				struct sieve_address address;
 				const char *part;
 			
-				address.local_part = addr->mailbox;
-				address.domain = addr->domain;
-
-				part = addrp->extract_from(&address);
-			
-				if ( part != NULL )
-					result = sieve_match_value(mctx, part, strlen(part));
+				if ( addr->domain != NULL ) {
+					address.local_part = addr->mailbox;
+					address.domain = addr->domain;
+	
+					part = addrp->extract_from(&address);
 
+					if ( part != NULL )
+						result = sieve_match_value(mctx, part, strlen(part));
+				}
 				addr = addr->next;
 			}
 		}
@@ -340,8 +341,8 @@ bool sieve_addrmatch_default_get_optionals
 static const char *addrp_all_extract_from
 	(const struct sieve_address *address)
 {
-	const char *local_part = address->local_part == NULL ? "" : address->local_part;
-	const char *domain = address->domain == NULL ? "" : address->domain;
+	const char *local_part = address->local_part;
+	const char *domain = address->domain;
 
 	return t_strconcat(local_part, "@", domain, NULL);
 }
diff --git a/tests/address.svtest b/tests/address.svtest
index 8842c058c99141051f02faae1d8f4d57f531b253..2b54bb06ec6bb24ddb7d12b324bc626191a6fa12 100644
--- a/tests/address.svtest
+++ b/tests/address.svtest
@@ -58,6 +58,29 @@ test "Invalid address list" {
 	}	
 }
 
+/*
+ * Undisclosed recipients
+ */
+
+test_set "message" text:
+From: stephan@
+To: undisclosed-recipients:;
+Subject: Invalid addresses
+
+Test.
+.
+;
+
+test "Undisclosed recipients" {
+    if address :is :domain "to" "undisclosed-recipients:;" {
+        test_fail ":domain matched group name";
+    }
+
+    if address :is :localpart "to" "undisclosed-recipients:;" {
+        test_fail ":localpart matched group name";
+    }
+}
+
 /*
  * Strange
  */
@@ -84,3 +107,5 @@ test "Questionable address" {
 		test_fail "message domain not recognized";
 	}
 }
+
+
diff --git a/tests/extensions/subaddress/basic.svtest b/tests/extensions/subaddress/basic.svtest
index 1292ed0bd9aaa5e38102aa9bd5e6aaef44e001e7..695d2999771b79f7b7e1e83558bc28ee0e0950ed 100644
--- a/tests/extensions/subaddress/basic.svtest
+++ b/tests/extensions/subaddress/basic.svtest
@@ -14,7 +14,7 @@ Test!
 test_set "envelope.to" "friep+frop@dovecot.org";
 test_set "envelope.from" "list+request@lists.dovecot.org";
 
-test "USER-message-from" {
+test "Address from :user" {
 	if not address :is :user "from" "stephan" {
 		test_fail "wrong user part extracted";
 	}
@@ -24,7 +24,7 @@ test "USER-message-from" {
 	}
 }
 
-test "DETAIL-message-from" {
+test "Address from :detail" {
 	if not address :is :detail "from" "sieve" {
 		test_fail "wrong user part extracted";
 	}
@@ -34,7 +34,7 @@ test "DETAIL-message-from" {
 	}
 }
 
-test "USER-message-to" {
+test "Address to :user" {
 	if not address :contains :user "to" "est" {
 		test_fail "wrong user part extracted";
 	}
@@ -44,7 +44,7 @@ test "USER-message-to" {
 	}
 }
 
-test "DETAIL-message-to" {
+test "Address to :detail" {
 	if not address :contains :detail "to" "fai" {
 		test_fail "wrong user part extracted";
 	}
@@ -55,7 +55,7 @@ test "DETAIL-message-to" {
 }
 
 
-test "ENVELOPE-to" {
+test "Envelope :user" {
     if not envelope :is :user "to" "friep" {
         test_fail "wrong user part extracted 1";
     }
@@ -69,7 +69,7 @@ test "ENVELOPE-to" {
     }
 }
 
-test "ENVELOPE-from" {
+test "Envelope :detail" {
     if not envelope :comparator "i;ascii-casemap" :contains :detail "from" "QUES" {
         test_fail "wrong user part extracted";
     }
@@ -78,3 +78,22 @@ test "ENVELOPE-from" {
         test_fail "address test failed";
     }
 }
+
+test_set "message" text:
+From: frop@examples.com
+To: undisclosed-recipients:;
+Subject: subaddress test
+
+Test!
+.
+;
+
+test "Undisclosed-recipients" {
+	if address :detail :contains "to" "undisclosed-recipients" {
+		test_fail ":detail matched group name";
+	}
+
+	if address :user :contains "to" "undisclosed-recipients" {
+		test_fail ":user matched group name";
+	}
+}