feat: fix backend some error;fix frontend display error

backend/saveEmail.js

@@ -1,10 +1,24 @@
 const { simpleParser } = require('mailparser');
 const db = require('./db');
 
+// Helper function to convert stream to buffer
+function streamToBuffer(stream) {
+    return new Promise((resolve, reject) => {
+        const chunks = [];
+        stream.on('data', (chunk) => chunks.push(chunk));
+        stream.on('error', reject);
+        stream.on('end', () => resolve(Buffer.concat(chunks)));
+    });
+}
+
 async function saveEmail(stream) {
     try {
-        const parsed = await simpleParser(stream);
-        const rawEmail = stream.toString(); // Or handle stream to buffer conversion appropriately
+        // First, buffer the entire stream
+        const emailBuffer = await streamToBuffer(stream);
+        
+        // Now, parse the buffered email content
+        const parsed = await simpleParser(emailBuffer);
+        const rawEmail = emailBuffer.toString();
 
         const recipient = parsed.to ? parsed.to.text : 'undisclosed-recipients';
         const sender = parsed.from ? parsed.from.text : 'unknown-sender';