diff --git a/notifications/event/type.go b/notifications/event/type.go
index 317f695..6acd973 100644
--- a/notifications/event/type.go
+++ b/notifications/event/type.go
@@ -17,11 +17,6 @@ const (
 	TypeAcknowledgementCleared // acknowledgement-cleared
 	TypeAcknowledgementSet     // acknowledgement-set
 	TypeCustom                 // custom
-	TypeDowntimeEnd            // downtime-end
-	TypeDowntimeRemoved        // downtime-removed
-	TypeDowntimeStart          // downtime-start
-	TypeFlappingEnd            // flapping-end
-	TypeFlappingStart          // flapping-start
 	TypeIncidentAge            // incident-age
 	TypeMute                   // mute
 	TypeState                  // state
diff --git a/notifications/event/type_string.go b/notifications/event/type_string.go
index b360f2b..116be56 100644
--- a/notifications/event/type_string.go
+++ b/notifications/event/type_string.go
@@ -12,25 +12,21 @@ func _() {
 	_ = x[TypeAcknowledgementCleared-1]
 	_ = x[TypeAcknowledgementSet-2]
 	_ = x[TypeCustom-3]
-	_ = x[TypeDowntimeEnd-4]
-	_ = x[TypeDowntimeRemoved-5]
-	_ = x[TypeDowntimeStart-6]
-	_ = x[TypeFlappingEnd-7]
-	_ = x[TypeFlappingStart-8]
-	_ = x[TypeIncidentAge-9]
-	_ = x[TypeMute-10]
-	_ = x[TypeState-11]
-	_ = x[TypeUnmute-12]
-	_ = x[typeMax-13]
+	_ = x[TypeIncidentAge-4]
+	_ = x[TypeMute-5]
+	_ = x[TypeState-6]
+	_ = x[TypeUnmute-7]
+	_ = x[typeMax-8]
 }
 
-const _Type_name = "unknownacknowledgement-clearedacknowledgement-setcustomdowntime-enddowntime-removeddowntime-startflapping-endflapping-startincident-agemutestateunmuteinternal"
+const _Type_name = "unknownacknowledgement-clearedacknowledgement-setcustomincident-agemutestateunmuteinternal"
 
-var _Type_index = [...]uint8{0, 7, 30, 49, 55, 67, 83, 97, 109, 123, 135, 139, 144, 150, 158}
+var _Type_index = [...]uint8{0, 7, 30, 49, 55, 67, 71, 76, 82, 90}
 
 func (i Type) String() string {
-	if i >= Type(len(_Type_index)-1) {
+	idx := int(i) - 0
+	if i < 0 || idx >= len(_Type_index)-1 {
 		return "Type(" + strconv.FormatInt(int64(i), 10) + ")"
 	}
-	return _Type_name[_Type_index[i]:_Type_index[i+1]]
+	return _Type_name[_Type_index[idx]:_Type_index[idx+1]]
 }
diff --git a/notifications/event/type_test.go b/notifications/event/type_test.go
index d435725..8a26e92 100644
--- a/notifications/event/type_test.go
+++ b/notifications/event/type_test.go
@@ -18,7 +18,6 @@ func TestType(t *testing.T) {
 			{Name: "State", Expected: `"state"`, Data: TypeState, Error: nil},
 			{Name: "Mute", Expected: `"mute"`, Data: TypeMute, Error: nil},
 			{Name: "Unmute", Expected: `"unmute"`, Data: TypeUnmute, Error: nil},
-			{Name: "DowntimeStart", Expected: `"downtime-start"`, Data: TypeDowntimeStart, Error: nil},
 		}
 
 		for _, tt := range testdata {
@@ -37,7 +36,6 @@ func TestType(t *testing.T) {
 			{Name: "State", Expected: TypeState, Data: `"state"`, Error: nil},
 			{Name: "Mute", Expected: TypeMute, Data: `"mute"`, Error: nil},
 			{Name: "Unmute", Expected: TypeUnmute, Data: `"unmute"`, Error: nil},
-			{Name: "DowntimeStart", Expected: TypeDowntimeStart, Data: `"downtime-start"`, Error: nil},
 			{Name: "Invalid", Expected: TypeUnknown, Data: `"invalid"`, Error: testutils.ErrorContains(`unknown type "invalid"`)},
 			{Name: "Invalid Unknown", Expected: TypeUnknown, Data: `"unknown"`, Error: testutils.ErrorContains(`unknown type "unknown"`)},
 		}
@@ -58,7 +56,6 @@ func TestType(t *testing.T) {
 			{Name: "State", Expected: TypeState, Data: `state`, Error: nil},
 			{Name: "Mute", Expected: TypeMute, Data: `mute`, Error: nil},
 			{Name: "Unmute", Expected: TypeUnmute, Data: `unmute`, Error: nil},
-			{Name: "DowntimeStart", Expected: TypeDowntimeStart, Data: `downtime-start`, Error: nil},
 			{Name: "Invalid", Expected: TypeUnknown, Data: `invalid`, Error: testutils.ErrorContains(`unknown type "invalid"`)},
 		}
 
@@ -78,7 +75,6 @@ func TestType(t *testing.T) {
 			{Name: "State", Expected: `state`, Data: TypeState, Error: nil},
 			{Name: "Mute", Expected: `mute`, Data: TypeMute, Error: nil},
 			{Name: "Unmute", Expected: `unmute`, Data: TypeUnmute, Error: nil},
-			{Name: "DowntimeStart", Expected: `downtime-start`, Data: TypeDowntimeStart, Error: nil},
 		}
 
 		for _, tt := range testdata {
diff --git a/notifications/plugin/plugin.go b/notifications/plugin/plugin.go
index a31a312..c24997c 100644
--- a/notifications/plugin/plugin.go
+++ b/notifications/plugin/plugin.go
@@ -324,11 +324,21 @@ func FormatSubject(req *NotificationRequest) string {
 	switch req.Event.Type {
 	case event.TypeState:
 		return fmt.Sprintf("[#%d] %s %s is %s", req.Incident.Id, req.Event.Type, req.Object.Name, req.Incident.Severity)
-	case event.TypeAcknowledgementCleared, event.TypeDowntimeRemoved:
+	case event.TypeAcknowledgementCleared:
 		if req.Incident != nil {
 			return fmt.Sprintf("[#%d] %s from %s", req.Incident.Id, req.Event.Type, req.Object.Name)
 		}
 		return fmt.Sprintf("%s from %s", req.Event.Type, req.Object.Name)
+	case event.TypeMute:
+		if req.Incident != nil {
+			return fmt.Sprintf("[#%d] %s is muted", req.Incident.Id, req.Object.Name)
+		}
+		return fmt.Sprintf("%s is muted", req.Object.Name)
+	case event.TypeUnmute:
+		if req.Incident != nil {
+			return fmt.Sprintf("[#%d] %s is unmuted", req.Incident.Id, req.Object.Name)
+		}
+		return fmt.Sprintf("%s is unmuted", req.Object.Name)
 	default:
 		if req.Incident != nil {
 			return fmt.Sprintf("[#%d] %s on %s", req.Incident.Id, req.Event.Type, req.Object.Name)