diff --git a/test_zoho_auth.py b/test_zoho_auth.py
index 2660fc4..29b163c 100644
--- a/test_zoho_auth.py
+++ b/test_zoho_auth.py
@@ -2,7 +2,8 @@ import datetime
 import unittest
 from freezegun import freeze_time
 from unittest.mock import patch, MagicMock
-from zoho_auth import ZohoToken
+from urllib.error import HTTPError
+from zoho_auth import ZohoToken, authenticate
 
 class TestZohoToken(unittest.TestCase):
     """Test the ZohoToken class"""
@@ -13,11 +14,12 @@ class TestZohoToken(unittest.TestCase):
         mock_response = MagicMock()
         mock_response.read.return_value.decode.return_value = '{"access_token": "mock_access_token", "expires_in": 3600}'
         mock_request.urlopen.return_value.__enter__.return_value = mock_response
+        token = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')
 
-        auth = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')
+        token.update_token()
 
         # Assert that the token was fetched
-        self.assertEqual(auth.get_token(), 'mock_access_token')
+        self.assertEqual(token.get_token(), 'mock_access_token')
         mock_request.Request.assert_called_with('https://accounts.zoho.com/oauth/v2/token?refresh_token=mock_refresh_token&client_id=mock_client_id&client_secret=mock_client_secret&grant_type=refresh_token', method='POST')
 
     @patch('zoho_auth.request')
@@ -28,16 +30,61 @@ class TestZohoToken(unittest.TestCase):
         mock_response.read.return_value.decode.return_value = '{"access_token": "mock_access_token", "expires_in": 3600}'
         mock_request.urlopen.return_value.__enter__.return_value = mock_response
 
-        auth = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')
-        self.assertEqual(auth.expires_at, datetime.datetime(2009, 6, 15, 10, 0, 0))
+        token = ZohoToken('mock_client_id', 'mock_client_secret', 'mock_refresh_token')
+        token.update_token()
 
+        self.assertEqual(token.expires_at, datetime.datetime(2009, 6, 15, 10, 0, 0))
         mock_response.read.return_value.decode.return_value = '{"access_token": "updated_mock_access_token", "expires_in": 3600}'
+
         frozen_time.tick(datetime.timedelta(seconds=3599))
-        token = auth.get_token()
-        self.assertEqual(token, 'mock_access_token')
+        self.assertEqual(token.get_token(), 'mock_access_token')
         frozen_time.tick(datetime.timedelta(seconds=1))
-        token = auth.get_token()
-        self.assertEqual(token, 'updated_mock_access_token')
+        self.assertEqual(token.get_token(), 'updated_mock_access_token')
+
+    @patch('zoho_auth.request')
+    def test_authenticate_calls_service(self, mock_request):
+        """Test that the authenticate function works"""
+        token = MagicMock()
+        token.get_token.return_value = 'mock_access_token'
+
+        mock_response = MagicMock()
+        mock_response.status = 200
+        mock_request.urlopen.return_value.__enter__.return_value = mock_response
+
+        ret_val = authenticate(token, 'ABCDEF1234567890')
+
+        mock_request.Request.assert_called_with('https://www.zohoapis.com/crm/v2/Contacts/search?criteria=%28Key_ID%3Aequals%3AABCDEF1234567890%29', method='GET', headers={
+            'Authorization': 'Zoho-oauthtoken mock_access_token',
+        })
+        self.assertTrue(ret_val)
+
+    @patch('zoho_auth.request')
+    def test_authenticate_fails_bad_key(self, mock_request):
+        """Test that the authenticate function works"""
+        token = MagicMock()
+        token.get_token.return_value = 'mock_access_token'
+
+        mock_response = MagicMock()
+        mock_response.status = 204
+        mock_request.urlopen.return_value.__enter__.return_value = mock_response
+
+        ret_val = authenticate(token, 'ABCDEF1234567890')
+
+        self.assertFalse(ret_val)
+
+
+    @patch('zoho_auth.request')
+    def test_authenticate_fails_when_server_is_down(self, mock_request):
+        """Test that the authenticate function works"""
+        token = MagicMock()
+        token.get_token.return_value = 'mock_access_token'
+
+        error = HTTPError('https://www.youtube.com/watch?v=dQw4w9WgXcQ', 403, 'Forbidden', {}, None)
+        mock_request.urlopen.return_value.__enter__.side_effect = error
+
+        ret_val = authenticate(token, 'ABCDEF1234567890')
+
+        self.assertFalse(ret_val)
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/zoho_auth.py b/zoho_auth.py
index 4417f2a..9a244ea 100644
--- a/zoho_auth.py
+++ b/zoho_auth.py
@@ -1,5 +1,6 @@
 import datetime
 import json
+from http import HTTPStatus
 from urllib import request
 from urllib.parse import urlencode
 from urllib.error import HTTPError
@@ -11,7 +12,6 @@ class ZohoToken:
         self.refresh_token = refresh_token
         self._access_token = None
         self.expires_at = None
-        self.update_token()
 
     def update_token(self):
         url = "https://accounts.zoho.com/oauth/v2/token?%s" % urlencode({
@@ -32,8 +32,6 @@ class ZohoToken:
         return self._access_token
 
 def authenticate(token, key):
-    ret = False
-
     url = "https://www.zohoapis.com/crm/v2/Contacts/search?%s" % urlencode({
         "criteria": "(Key_ID:equals:%s)" % key,
     })
@@ -43,10 +41,8 @@ def authenticate(token, key):
     print("Pinging server with key: %s (%s)" % (key, url))
     try:
         with request.urlopen(req) as response:
-            response_body = response.read()
-            if len(response_body) > 0:
-                ret = True
+            return response.status == HTTPStatus.OK
     except HTTPError as e:
         print("Error pinging server: %s" % e)
 
-    return ret
+    return False