diff --git a/extras/kolab_policy_spf b/extras/kolab_policy_spf
--- a/extras/kolab_policy_spf
+++ b/extras/kolab_policy_spf
@@ -7,6 +7,7 @@
 import json
 import time
 import sys
+import logging
 
 import requests
 
@@ -23,6 +24,7 @@
 
     while not end_of_request:
         if (time.time() - start_time) >= 10:
+            logging.warning("policy/spf rate-limited.")
             print("action=DEFER_IF_PERMIT Temporary error, try again later.\n")
             sys.stdout.flush()
             sys.exit(0)
@@ -57,6 +59,7 @@
             )
         # pylint: disable=broad-except
         except Exception:
+            logging.warning("policy/spf request failed.")
             print("action=DEFER_IF_PERMIT Temporary error, try again later.\n")
             sys.stdout.flush()
             sys.exit(0)
@@ -65,7 +68,8 @@
             R = json.loads(RESPONSE.text)
         # pylint: disable=broad-except
         except Exception:
-            print("action=DEFER_IF_PERMIT Temporary error, try again later.\n")
+            logging.warning("Failed to load json from policy/spf request.")
+            print("action=DEFER_IF_PERMIT Temporary SPF request error, try again later.\n")
             sys.stdout.flush()
             sys.exit(0)
 
@@ -73,10 +77,15 @@
             for prepend in R['prepend']:
                 print("action=PREPEND {0}".format(prepend))
 
+        if 'log' in R:
+            for line in R['log']:
+                logging.warning(line)
+
         if RESPONSE.ok:
             print("action={0}\n".format(R['response']))
         else:
             print("action={0} {1}\n".format(R['response'], R['reason']))
+            logging.warning("spf failed with reason: %s" % R['reason'])
 
         sys.stdout.flush()
         sys.exit(0)
diff --git a/src/app/Http/Controllers/API/V4/PolicyController.php b/src/app/Http/Controllers/API/V4/PolicyController.php
--- a/src/app/Http/Controllers/API/V4/PolicyController.php
+++ b/src/app/Http/Controllers/API/V4/PolicyController.php
@@ -298,7 +298,8 @@
             return response()->json(
                 [
                     'response' => 'DEFER_IF_PERMIT',
-                    'reason' => 'Temporary error. Please try again later.'
+                    'reason' => 'Temporary SPF check error. Please try again later.',
+                    'log' => ["SPF: Request without client_address: " . json_encode($data)]
                 ],
                 403
             );
@@ -313,7 +314,8 @@
             return response()->json(
                 [
                     'response' => 'DEFER_IF_PERMIT',
-                    'reason' => 'Temporary error. Please try again later.'
+                    'reason' => 'Temporary SPF check error. Please try again later.',
+                    'log' => ["SPF: Request without recognizable network: " . json_encode($data)]
                 ],
                 403
             );