diff --git c/whisper/whisperv6/events.go w/whisper/whisperv6/events.go
new file mode 100644
index 000000000..4f204ab5d
--- /dev/null
+++ w/whisper/whisperv6/events.go
@@ -0,0 +1,23 @@
+package whisperv6
+
+import (
+       "github.com/ethereum/go-ethereum/common"
+       "github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+// EventType used to define known envelope events.
+type EventType string
+
+const (
+       // EventEnvelopeSent fires when envelope was sent to a peer.
+       EventEnvelopeSent EventType = "envelope.sent"
+       // EventEnvelopeExpired fires when envelop expired
+       EventEnvelopeExpired EventType = "envelope.expired"
+)
+
+// EnvelopeEvent used for envelopes events.
+type EnvelopeEvent struct {
+       Event EventType
+       Hash  common.Hash
+       Peer  discover.NodeID
+}
diff --git i/whisper/whisperv6/peer.go w/whisper/whisperv6/peer.go
index 2bf1c905b..427127290 100644
--- i/whisper/whisperv6/peer.go
+++ w/whisper/whisperv6/peer.go
@@ -204,6 +204,11 @@ func (peer *Peer) broadcast() error {
 		// mark envelopes only if they were successfully sent
 		for _, e := range bundle {
 			peer.mark(e)
+			peer.host.envelopeFeed.Send(EnvelopeEvent{
+				Event: EventEnvelopeSent,
+				Hash:  e.Hash(),
+				Peer:  peer.peer.ID(), // specifically discover.NodeID because it can be pretty printed
+			})
 		}
 
 		log.Trace("broadcast", "num. messages", len(bundle))
diff --git i/whisper/whisperv6/whisper.go w/whisper/whisperv6/whisper.go
index 9aaf5687c..eb637b4ca 100644
--- i/whisper/whisperv6/whisper.go
+++ w/whisper/whisperv6/whisper.go
@@ -28,6 +28,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/rlp"
@@ -89,6 +90,8 @@ type Whisper struct {
 
 	mailServer     MailServer     // MailServer interface
 	envelopeTracer EnvelopeTracer // Service collecting envelopes metadata
+
+	envelopeFeed event.Feed
 }
 
 // New creates a Whisper client ready to communicate through the Ethereum P2P network.
@@ -133,6 +136,12 @@ func New(cfg *Config) *Whisper {
 	return whisper
 }
 
+// SubscribeEnvelopeEvents subscribes to envelopes feed.
+// In order to prevent blocking whisper producers events must be amply buffered.
+func (whisper *Whisper) SubscribeEnvelopeEvents(events chan<- EnvelopeEvent) event.Subscription {
+	return whisper.envelopeFeed.Subscribe(events)
+}
+
 // MinPow returns the PoW value required by this node.
 func (whisper *Whisper) MinPow() float64 {
 	val, exist := whisper.settings.Load(minPowIdx)
@@ -986,6 +995,10 @@ func (whisper *Whisper) expire() {
 			hashSet.Each(func(v interface{}) bool {
 				sz := whisper.envelopes[v.(common.Hash)].size()
 				delete(whisper.envelopes, v.(common.Hash))
+				whisper.envelopeFeed.Send(EnvelopeEvent{
+					Hash:  v.(common.Hash),
+					Event: EventEnvelopeExpired,
+				})
 				whisper.stats.messagesCleared++
 				whisper.stats.memoryCleared += sz
 				whisper.stats.memoryUsed -= sz