diff --git a/api/libs/smtp.py b/api/libs/smtp.py
index 2325d69a41..35561f071c 100644
--- a/api/libs/smtp.py
+++ b/api/libs/smtp.py
@@ -28,7 +28,8 @@ class SMTPClient:
             else:
                 smtp = smtplib.SMTP(self.server, self.port, timeout=10)
 
-            if self.username and self.password:
+            # Only authenticate if both username and password are non-empty
+            if self.username and self.password and self.username.strip() and self.password.strip():
                 smtp.login(self.username, self.password)
 
             msg = MIMEMultipart()