Add rspamd as a second spam filter alongside SpamAssassin

Closes: #36

pkg/analyzer/parser.go

@@ -264,6 +264,26 @@ func (e *EmailMessage) GetSpamAssassinHeaders() map[string]string {
 	return headers
 }
 
+// GetRspamdHeaders extracts rspamd-related headers
+func (e *EmailMessage) GetRspamdHeaders() map[string]string {
+	headers := make(map[string]string)
+
+	rspamdHeaders := []string{
+		"X-Spamd-Result",
+		"X-Rspamd-Score",
+		"X-Rspamd-Action",
+		"X-Rspamd-Server",
+	}
+
+	for _, headerName := range rspamdHeaders {
+		if value := e.Header.Get(headerName); value != "" {
+			headers[headerName] = value
+		}
+	}
+
+	return headers
+}
+
 // GetTextParts returns all text/plain parts
 func (e *EmailMessage) GetTextParts() []MessagePart {
 	return filterParts(e.Parts, func(p MessagePart) bool {