feat: Add catch-all recipient support for unmatched email addresses

backend.go

@@ -18,6 +18,28 @@ type Backend struct {
 	config *Config
 }
 
+func (bkd *Backend) sendNotification(recipient ConfigRecipient, email ReceivedEmail) error {
+	urlParams := url.Values{
+		"title": {email.Msg.Header.Get("Subject")},
+	}
+
+	destinationURL := recipient.GetTargetURL()
+	destinationURL.RawQuery = urlParams.Encode()
+
+	body, err := email.Body()
+	if err != nil {
+		slog.Error("Error getting email body", slog.String("err", err.Error()))
+		return fmt.Errorf("failed to get email body: %w", err)
+	}
+
+	if err := shoutrrr.Send(destinationURL.String(), body); err != nil {
+		slog.Error("Error sending message", slog.String("err", err.Error()))
+		return fmt.Errorf("failed to send notification: %w", err)
+	}
+
+	return nil
+}
+
 func (bkd *Backend) NewSession(c *smtp.Conn) (smtp.Session, error) {
 	return &Session{
 		forwarderFunc: bkd.forwardEmail,
@@ -28,30 +50,29 @@ func (bkd *Backend) NewSession(c *smtp.Conn) (smtp.Session, error) {
 func (bkd *Backend) forwardEmail(email ReceivedEmail) error {
 	slog.Info("forwading message", slog.String("to", strings.Join(email.Recipients, ",")))
 
+	// Try to match configured recipients first
+	matched := false
 	for _, r := range bkd.config.Recipients {
 		for _, a := range email.Recipients {
 			if slices.Contains(r.Addresses, a) {
-				urlParams := url.Values{
+				if err := bkd.sendNotification(r, email); err != nil {
-					"title": {email.Msg.Header.Get("Subject")},
+					return err
 				}
-
+				matched = true
-				destinationURL := r.GetTargetURL()
-				destinationURL.RawQuery = urlParams.Encode()
-
-				body, err := email.Body()
-				if err != nil {
-					slog.Error("Error getting email body", slog.String("err", err.Error()))
-					continue
-				}
-
-				if err := shoutrrr.Send(destinationURL.String(), body); err != nil {
-					slog.Error("Error sending message", slog.String("err", err.Error()))
-					continue
-				}
-
 				break
 			}
 		}
+		if matched {
+			break
+		}
+	}
+
+	// If no recipient matched and catch-all is configured, use it
+	if !matched && bkd.config.CatchAll != nil {
+		slog.Info("using catch-all recipient for unmatched email")
+		if err := bkd.sendNotification(*bkd.config.CatchAll, email); err != nil {
+			return err
+		}
 	}
 
 	return nil