diff --git a/internal/mail/router.go b/internal/mail/router.go
index 771dc72b..b679a227 100644
--- a/internal/mail/router.go
+++ b/internal/mail/router.go
@@ -991,47 +991,85 @@ func (r *Router) GetMailbox(address string) (*Mailbox, error) {
 
 // notifyRecipient sends a notification to a recipient's tmux session.
 // Uses NudgeSession to add the notification to the agent's conversation history.
-// Supports mayor/, rig/polecat, and rig/refinery addresses.
+// Supports mayor/, deacon/, rig/crew/name, rig/polecats/name, and rig/name addresses.
 func (r *Router) notifyRecipient(msg *Message) error {
-	sessionID := addressToSessionID(msg.To)
-	if sessionID == "" {
+	sessionIDs := addressToSessionIDs(msg.To)
+	if len(sessionIDs) == 0 {
 		return nil // Unable to determine session ID
 	}
 
-	// Check if session exists
-	hasSession, err := r.tmux.HasSession(sessionID)
-	if err != nil || !hasSession {
-		return nil // No active session, skip notification
+	// Try each possible session ID until we find one that exists.
+	// This handles the ambiguity where canonical addresses (rig/name) don't
+	// distinguish between crew workers (gt-rig-crew-name) and polecats (gt-rig-name).
+	for _, sessionID := range sessionIDs {
+		hasSession, err := r.tmux.HasSession(sessionID)
+		if err != nil || !hasSession {
+			continue
+		}
+
+		// Send notification to the agent's conversation history
+		notification := fmt.Sprintf("📬 You have new mail from %s. Subject: %s. Run 'gt mail inbox' to read.", msg.From, msg.Subject)
+		return r.tmux.NudgeSession(sessionID, notification)
 	}
 
-	// Send notification to the agent's conversation history
-	notification := fmt.Sprintf("📬 You have new mail from %s. Subject: %s. Run 'gt mail inbox' to read.", msg.From, msg.Subject)
-	return r.tmux.NudgeSession(sessionID, notification)
+	return nil // No active session found
 }
 
-// addressToSessionID converts a mail address to a tmux session ID.
-// Returns empty string if address format is not recognized.
-func addressToSessionID(address string) string {
+// addressToSessionIDs converts a mail address to possible tmux session IDs.
+// Returns multiple candidates since the canonical address format (rig/name)
+// doesn't distinguish between crew workers (gt-rig-crew-name) and polecats
+// (gt-rig-name). The caller should try each and use the one that exists.
+//
+// This supersedes the approach in PR #896 which only handled slash-to-dash
+// conversion but didn't address the crew/polecat ambiguity.
+func addressToSessionIDs(address string) []string {
 	// Mayor address: "mayor/" or "mayor"
 	if strings.HasPrefix(address, "mayor") {
-		return session.MayorSessionName()
+		return []string{session.MayorSessionName()}
 	}
 
 	// Deacon address: "deacon/" or "deacon"
 	if strings.HasPrefix(address, "deacon") {
-		return session.DeaconSessionName()
+		return []string{session.DeaconSessionName()}
 	}
 
-	// Rig-based address: "rig/target"
+	// Rig-based address: "rig/target" or "rig/crew/name" or "rig/polecats/name"
 	parts := strings.SplitN(address, "/", 2)
 	if len(parts) != 2 || parts[1] == "" {
-		return ""
+		return nil
 	}
 
 	rig := parts[0]
 	target := parts[1]
 
-	// Polecat: gt-rig-polecat
-	// Refinery: gt-rig-refinery (if refinery has its own session)
-	return fmt.Sprintf("gt-%s-%s", rig, target)
+	// If target already has crew/ or polecats/ prefix, use it directly
+	// e.g., "gastown/crew/holden" → "gt-gastown-crew-holden"
+	if strings.HasPrefix(target, "crew/") || strings.HasPrefix(target, "polecats/") {
+		return []string{fmt.Sprintf("gt-%s-%s", rig, strings.ReplaceAll(target, "/", "-"))}
+	}
+
+	// Special cases that don't need crew variant
+	if target == "witness" || target == "refinery" {
+		return []string{fmt.Sprintf("gt-%s-%s", rig, target)}
+	}
+
+	// For normalized addresses like "gastown/holden", try both:
+	// 1. Crew format: gt-gastown-crew-holden
+	// 2. Polecat format: gt-gastown-holden
+	// Return crew first since crew workers are more commonly missed.
+	return []string{
+		session.CrewSessionName(rig, target),    // gt-rig-crew-name
+		session.PolecatSessionName(rig, target), // gt-rig-name
+	}
+}
+
+// addressToSessionID converts a mail address to a tmux session ID.
+// Returns empty string if address format is not recognized.
+// Deprecated: Use addressToSessionIDs for proper crew/polecat handling.
+func addressToSessionID(address string) string {
+	ids := addressToSessionIDs(address)
+	if len(ids) == 0 {
+		return ""
+	}
+	return ids[0]
 }
diff --git a/internal/mail/router_test.go b/internal/mail/router_test.go
index 0132bd6c..9d9fdf52 100644
--- a/internal/mail/router_test.go
+++ b/internal/mail/router_test.go
@@ -87,7 +87,52 @@ func TestIsTownLevelAddress(t *testing.T) {
 	}
 }
 
+func TestAddressToSessionIDs(t *testing.T) {
+	tests := []struct {
+		address string
+		want    []string
+	}{
+		// Town-level addresses - single session
+		{"mayor", []string{"hq-mayor"}},
+		{"mayor/", []string{"hq-mayor"}},
+		{"deacon", []string{"hq-deacon"}},
+
+		// Rig singletons - single session (no crew/polecat ambiguity)
+		{"gastown/refinery", []string{"gt-gastown-refinery"}},
+		{"beads/witness", []string{"gt-beads-witness"}},
+
+		// Ambiguous addresses - try both crew and polecat variants
+		{"gastown/Toast", []string{"gt-gastown-crew-Toast", "gt-gastown-Toast"}},
+		{"beads/ruby", []string{"gt-beads-crew-ruby", "gt-beads-ruby"}},
+
+		// Explicit crew/polecat - single session
+		{"gastown/crew/max", []string{"gt-gastown-crew-max"}},
+		{"gastown/polecats/nux", []string{"gt-gastown-polecats-nux"}},
+
+		// Invalid addresses - empty result
+		{"gastown/", nil},  // Empty target
+		{"gastown", nil},   // No slash
+		{"", nil},          // Empty address
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.address, func(t *testing.T) {
+			got := addressToSessionIDs(tt.address)
+			if len(got) != len(tt.want) {
+				t.Errorf("addressToSessionIDs(%q) = %v, want %v", tt.address, got, tt.want)
+				return
+			}
+			for i, v := range got {
+				if v != tt.want[i] {
+					t.Errorf("addressToSessionIDs(%q)[%d] = %q, want %q", tt.address, i, v, tt.want[i])
+				}
+			}
+		})
+	}
+}
+
 func TestAddressToSessionID(t *testing.T) {
+	// Deprecated wrapper - returns first candidate from addressToSessionIDs
 	tests := []struct {
 		address string
 		want    string
@@ -96,7 +141,7 @@ func TestAddressToSessionID(t *testing.T) {
 		{"mayor/", "hq-mayor"},
 		{"deacon", "hq-deacon"},
 		{"gastown/refinery", "gt-gastown-refinery"},
-		{"gastown/Toast", "gt-gastown-Toast"},
+		{"gastown/Toast", "gt-gastown-crew-Toast"}, // First candidate is crew
 		{"beads/witness", "gt-beads-witness"},
 		{"gastown/", ""},   // Empty target
 		{"gastown", ""},    // No slash