BugFixes

email-worker-nodejs/message-processor.ts

@@ -312,17 +312,38 @@ export class MessageProcessor {
 // ---------------------------------------------------------------------------
 
 /**
- * Add X-SES-Worker-Processed header to raw email bytes.
+ * Add X-SES-Worker-Processed header to raw email bytes using Buffer manipulation.
+ * More robust and memory efficient than toString().
  */
 function addProcessedHeader(raw: Buffer): Buffer {
-  const str = raw.toString('utf-8');
-  const sep = str.match(/\r?\n\r?\n/);
-  if (!sep || sep.index === undefined) return raw;
+  // Wir suchen nach dem Ende der Header: Double Newline (\r\n\r\n oder \n\n)
+  let headerEndIndex = -1;
+  
+  // Effiziente Suche im Buffer
+  for (let i = 0; i < raw.length - 3; i++) {
+    // Check für \r\n\r\n
+    if (raw[i] === 0x0d && raw[i+1] === 0x0a && raw[i+2] === 0x0d && raw[i+3] === 0x0a) {
+      headerEndIndex = i;
+      break;
+    }
+    // Check für \n\n (Unix style, seltener bei E-Mail aber möglich)
+    if (raw[i] === 0x0a && raw[i+1] === 0x0a) {
+      headerEndIndex = i;
+      break;
+    }
+  }
 
-  const before = str.slice(0, sep.index);
-  const after = str.slice(sep.index);
-  return Buffer.from(
-    `${before}\r\nX-SES-Worker-Processed: delivered${after}`,
-    'utf-8',
-  );
+  // Falls keine Header-Trennung gefunden wurde (kaputte Mail?), hängen wir es einfach vorne an
+  if (headerEndIndex === -1) {
+    const headerLine = Buffer.from('X-SES-Worker-Processed: delivered\r\n', 'utf-8');
+    return Buffer.concat([headerLine, raw]);
+  }
+
+  // Wir fügen den Header VOR der leeren Zeile ein
+  const before = raw.subarray(0, headerEndIndex);
+  const after = raw.subarray(headerEndIndex);
+  
+  const newHeader = Buffer.from('\r\nX-SES-Worker-Processed: delivered', 'utf-8');
+
+  return Buffer.concat([before, newHeader, after]);
 }