diff --git a/whisper/whisperv5/filter.go b/whisper/whisperv5/filter.go
index 5775462a7a..81c4c9a65c 100644
--- a/whisper/whisperv5/filter.go
+++ b/whisper/whisperv5/filter.go
@@ -124,7 +124,9 @@ func (fs *Filters) NotifyWatchers(env *Envelope, p2pMessage bool) {
 
 		if match && msg != nil {
 			log.Trace("processing message: decrypted", "hash", env.Hash().Hex())
-			watcher.Trigger(msg)
+			if watcher.Src == nil || IsPubKeyEqual(msg.Src, watcher.Src) {
+				watcher.Trigger(msg)
+			}
 		}
 	}
 }
@@ -177,9 +179,6 @@ func (f *Filter) MatchMessage(msg *ReceivedMessage) bool {
 	if f.PoW > 0 && msg.PoW < f.PoW {
 		return false
 	}
-	if f.Src != nil && !IsPubKeyEqual(msg.Src, f.Src) {
-		return false
-	}
 
 	if f.expectsAsymmetricEncryption() && msg.isAsymmetricEncryption() {
 		return IsPubKeyEqual(&f.KeyAsym.PublicKey, msg.Dst) && f.MatchTopic(msg.Topic)
diff --git a/whisper/whisperv5/filter_test.go b/whisper/whisperv5/filter_test.go
index 3fcb4eb9cb..c2e4f7b465 100644
--- a/whisper/whisperv5/filter_test.go
+++ b/whisper/whisperv5/filter_test.go
@@ -223,7 +223,6 @@ func TestInstallIdenticalFilters(t *testing.T) {
 
 func TestSymmetricSendCycle(t *testing.T) {
 	InitSingleTest()
-	//mrand.Seed(1505987108)
 
 	w := New(&DefaultConfig)
 	defer w.SetMinimumPoW(DefaultMinimumPoW)
@@ -235,6 +234,7 @@ func TestSymmetricSendCycle(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed generateMessageParams with seed %d: %s.", seed, err)
 	}
+	filter1.PoW = DefaultMinimumPoW
 
 	// Copy the first filter since some of its fields
 	// are randomly gnerated.
@@ -300,7 +300,6 @@ func TestSymmetricSendCycle(t *testing.T) {
 	// check w.messages()
 	time.Sleep(100 * time.Millisecond)
 	mail1 := filter1.Retrieve()
-
 	mail2 := filter2.Retrieve()
 	if len(mail2) == 0 {
 		t.Fatalf("did not receive any email for filter 2")
@@ -311,6 +310,140 @@ func TestSymmetricSendCycle(t *testing.T) {
 
 }
 
+func TestSymmetricSendWithoutAKey(t *testing.T) {
+	InitSingleTest()
+
+	w := New(&DefaultConfig)
+	defer w.SetMinimumPoW(DefaultMinimumPoW)
+	defer w.SetMaxMessageSize(DefaultMaxMessageSize)
+	w.Start(nil)
+	defer w.Stop()
+
+	filter, err := generateFilter(t, true)
+	if err != nil {
+		t.Fatalf("failed generateMessageParams with seed %d: %s.", seed, err)
+	}
+	filter.PoW = DefaultMinimumPoW
+
+	params, err := generateMessageParams()
+	if err != nil {
+		t.Fatalf("failed generateMessageParams with seed %d: %s.", seed, err)
+	}
+
+	filter.Src = nil
+
+	params.KeySym = filter.KeySym
+	params.Topic = BytesToTopic(filter.Topics[2])
+	params.PoW = filter.PoW
+	params.WorkTime = 10
+	params.TTL = 50
+	msg, err := NewSentMessage(params)
+	if err != nil {
+		t.Fatalf("failed to create new message with seed %d: %s.", seed, err)
+	}
+	env, err := msg.Wrap(params)
+	if err != nil {
+		t.Fatalf("failed Wrap with seed %d: %s.", seed, err)
+	}
+
+	_, err = w.Subscribe(filter)
+	if err != nil {
+		t.Fatalf("failed subscribe 1 with seed %d: %s.", seed, err)
+	}
+
+	err = w.Send(env)
+	if err != nil {
+		t.Fatalf("Failed sending envelope with PoW %.06f (seed %d): %s", env.PoW(), seed, err)
+	}
+
+	// wait till received or timeout
+	var received bool
+	for j := 0; j < 200; j++ {
+		time.Sleep(10 * time.Millisecond)
+		if len(w.Envelopes()) > 0 {
+			received = true
+			break
+		}
+	}
+
+	if !received {
+		t.Fatalf("did not receive the sent envelope, seed: %d.", seed)
+	}
+
+	// check w.messages()
+	time.Sleep(100 * time.Millisecond)
+	mail := filter.Retrieve()
+	if len(mail) == 0 {
+		t.Fatalf("did not receive message in spite of not setting a public key")
+	}
+}
+
+func TestSymmetricSendKeyMismatch(t *testing.T) {
+	InitSingleTest()
+
+	w := New(&DefaultConfig)
+	defer w.SetMinimumPoW(DefaultMinimumPoW)
+	defer w.SetMaxMessageSize(DefaultMaxMessageSize)
+	w.Start(nil)
+	defer w.Stop()
+
+	filter, err := generateFilter(t, true)
+	if err != nil {
+		t.Fatalf("failed generateMessageParams with seed %d: %s.", seed, err)
+	}
+	filter.PoW = DefaultMinimumPoW
+
+	params, err := generateMessageParams()
+	if err != nil {
+		t.Fatalf("failed generateMessageParams with seed %d: %s.", seed, err)
+	}
+
+	params.KeySym = filter.KeySym
+	params.Topic = BytesToTopic(filter.Topics[2])
+	params.PoW = filter.PoW
+	params.WorkTime = 10
+	params.TTL = 50
+	msg, err := NewSentMessage(params)
+	if err != nil {
+		t.Fatalf("failed to create new message with seed %d: %s.", seed, err)
+	}
+	env, err := msg.Wrap(params)
+	if err != nil {
+		t.Fatalf("failed Wrap with seed %d: %s.", seed, err)
+	}
+
+	_, err = w.Subscribe(filter)
+	if err != nil {
+		t.Fatalf("failed subscribe 1 with seed %d: %s.", seed, err)
+	}
+
+	err = w.Send(env)
+	if err != nil {
+		t.Fatalf("Failed sending envelope with PoW %.06f (seed %d): %s", env.PoW(), seed, err)
+	}
+
+	// wait till received or timeout
+	var received bool
+	for j := 0; j < 200; j++ {
+		time.Sleep(10 * time.Millisecond)
+		if len(w.Envelopes()) > 0 {
+			received = true
+			break
+		}
+	}
+
+	if !received {
+		t.Fatalf("did not receive the sent envelope, seed: %d.", seed)
+	}
+
+	// check w.messages()
+	time.Sleep(100 * time.Millisecond)
+	mail := filter.Retrieve()
+	if len(mail) > 0 {
+		t.Fatalf("received a message when keys weren't matching")
+	}
+}
+
 func TestComparePubKey(t *testing.T) {
 	InitSingleTest()
 
@@ -524,11 +657,6 @@ func TestMatchMessageSym(t *testing.T) {
 		t.Fatalf("failed Open with seed %d.", seed)
 	}
 
-	// Src mismatch
-	if f.MatchMessage(msg) {
-		t.Fatalf("failed MatchMessage(src mismatch) with seed %d.", seed)
-	}
-
 	// Src: match
 	*f.Src.X = *params.Src.PublicKey.X
 	*f.Src.Y = *params.Src.PublicKey.Y
@@ -622,11 +750,6 @@ func TestMatchMessageAsym(t *testing.T) {
 		t.Fatalf("failed to open with seed %d.", seed)
 	}
 
-	// Src mismatch
-	if f.MatchMessage(msg) {
-		t.Fatalf("failed MatchMessage(src mismatch) with seed %d.", seed)
-	}
-
 	// Src: match
 	*f.Src.X = *params.Src.PublicKey.X
 	*f.Src.Y = *params.Src.PublicKey.Y