diff --git a/downstream.go b/downstream.go
index b6129d2..4707591 100644
--- a/downstream.go
+++ b/downstream.go
@@ -1030,9 +1030,8 @@ func (dc *downstreamConn) sendTargetBacklog(net *network, target, msgID string)
 	if dc.caps["draft/chathistory"] || dc.user.msgStore == nil {
 		return
 	}
-	if ch := net.channels.Value(target); ch != nil && ch.Detached {
-		return
-	}
+
+	ch := net.channels.Value(target)
 
 	limit := 4000
 	targetCM := net.casemap(target)
@@ -1056,10 +1055,16 @@ func (dc *downstreamConn) sendTargetBacklog(net *network, target, msgID string)
 			continue
 		}
 
-		if dc.caps["batch"] {
-			msg.Tags["batch"] = irc.TagValue(batchRef)
+		if ch != nil && ch.Detached {
+			if net.detachedMessageNeedsRelay(ch, msg) {
+				dc.relayDetachedMessage(net, msg)
+			}
+		} else {
+			if dc.caps["batch"] {
+				msg.Tags["batch"] = irc.TagValue(batchRef)
+			}
+			dc.SendMessage(dc.marshalMessage(msg, net))
 		}
-		dc.SendMessage(dc.marshalMessage(msg, net))
 	}
 
 	if dc.caps["batch"] {
@@ -1071,6 +1076,20 @@ func (dc *downstreamConn) sendTargetBacklog(net *network, target, msgID string)
 	}
 }
 
+func (dc *downstreamConn) relayDetachedMessage(net *network, msg *irc.Message) {
+	if msg.Command != "PRIVMSG" && msg.Command != "NOTICE" {
+		return
+	}
+
+	sender := msg.Prefix.Name
+	target, text := msg.Params[0], msg.Params[1]
+	if net.isHighlight(msg) {
+		sendServiceNOTICE(dc, fmt.Sprintf("highlight in %v: <%v> %v", dc.marshalEntity(net, target), sender, text))
+	} else {
+		sendServiceNOTICE(dc, fmt.Sprintf("message in %v: <%v> %v", dc.marshalEntity(net, target), sender, text))
+	}
+}
+
 func (dc *downstreamConn) runUntilRegistered() error {
 	for !dc.registered {
 		msg, err := dc.ReadMessage()
diff --git a/upstream.go b/upstream.go
index 8eaee2e..b61fc67 100644
--- a/upstream.go
+++ b/upstream.go
@@ -391,10 +391,10 @@ func (uc *upstreamConn) handleMessage(msg *irc.Message) error {
 			ch := uc.network.channels.Value(target)
 			if ch != nil {
 				if ch.Detached {
-					uc.handleDetachedMessage(msg.Prefix.Name, text, ch)
+					uc.handleDetachedMessage(ch, msg)
 				}
 
-				highlight := msg.Prefix.Name != uc.nick && isHighlight(text, uc.nick)
+				highlight := uc.network.isHighlight(msg)
 				if ch.DetachOn == FilterMessage || ch.DetachOn == FilterDefault || (ch.DetachOn == FilterHighlight && highlight) {
 					uc.updateChannelAutoDetach(target)
 				}
@@ -1437,18 +1437,13 @@ func (uc *upstreamConn) handleMessage(msg *irc.Message) error {
 	return nil
 }
 
-func (uc *upstreamConn) handleDetachedMessage(sender string, text string, ch *Channel) {
-	highlight := sender != uc.nick && isHighlight(text, uc.nick)
-	if ch.RelayDetached == FilterMessage || ((ch.RelayDetached == FilterHighlight || ch.RelayDetached == FilterDefault) && highlight) {
+func (uc *upstreamConn) handleDetachedMessage(ch *Channel, msg *irc.Message) {
+	if uc.network.detachedMessageNeedsRelay(ch, msg) {
 		uc.forEachDownstream(func(dc *downstreamConn) {
-			if highlight {
-				sendServiceNOTICE(dc, fmt.Sprintf("highlight in %v: <%v> %v", dc.marshalEntity(uc.network, ch.Name), sender, text))
-			} else {
-				sendServiceNOTICE(dc, fmt.Sprintf("message in %v: <%v> %v", dc.marshalEntity(uc.network, ch.Name), sender, text))
-			}
+			dc.relayDetachedMessage(uc.network, msg)
 		})
 	}
-	if ch.ReattachOn == FilterMessage || (ch.ReattachOn == FilterHighlight && highlight) {
+	if ch.ReattachOn == FilterMessage || (ch.ReattachOn == FilterHighlight && uc.network.isHighlight(msg)) {
 		uc.network.attach(ch)
 		if err := uc.srv.db.StoreChannel(uc.network.ID, ch); err != nil {
 			uc.logger.Printf("failed to update channel %q: %v", ch.Name, err)
@@ -1743,12 +1738,10 @@ func (uc *upstreamConn) produce(target string, msg *irc.Message, origin *downstr
 
 	// Don't forward messages if it's a detached channel
 	ch := uc.network.channels.Value(target)
-	if ch != nil && ch.Detached {
-		return
-	}
+	detached := ch != nil && ch.Detached
 
 	uc.forEachDownstream(func(dc *downstreamConn) {
-		if dc != origin || dc.caps["echo-message"] {
+		if !detached && (dc != origin || dc.caps["echo-message"]) {
 			dc.sendMessageWithID(dc.marshalMessage(msg, uc.network), msgID)
 		} else {
 			dc.advanceMessageWithID(msg, msgID)
diff --git a/user.go b/user.go
index e2e06ee..ac3facd 100644
--- a/user.go
+++ b/user.go
@@ -351,6 +351,27 @@ func (net *network) storeClientDeliveryReceipts(clientName string) {
 	}
 }
 
+func (net *network) isHighlight(msg *irc.Message) bool {
+	if msg.Command != "PRIVMSG" && msg.Command != "NOTICE" {
+		return false
+	}
+
+	text := msg.Params[1]
+
+	nick := net.Nick
+	if net.conn != nil {
+		nick = net.conn.nick
+	}
+
+	// TODO: use case-mapping aware comparison here
+	return msg.Prefix.Name != nick && isHighlight(text, nick)
+}
+
+func (net *network) detachedMessageNeedsRelay(ch *Channel, msg *irc.Message) bool {
+	highlight := net.isHighlight(msg)
+	return ch.RelayDetached == FilterMessage || ((ch.RelayDetached == FilterHighlight || ch.RelayDetached == FilterDefault) && highlight)
+}
+
 type user struct {
 	User
 	srv    *Server