Update app.py

app.py

@@ -22,6 +22,7 @@ def send_email(subject, body):
     # Gửi email qua SMTP server
     try:
         with smtplib.SMTP_SSL('smtp.gmail.com', 587) as server:
+            server.starttls()
             server.login(sender_email, password)
             server.sendmail(sender_email, receiver_email, msg.as_string())
             print("Email sent successfully.")