diff --git a/groups/locations.py b/groups/locations.py
index 6324c7c..961ddc8 100644
--- a/groups/locations.py
+++ b/groups/locations.py
@@ -22,7 +22,7 @@ groups['gce'] = {
             # It's fine to do this without authentificating to the relayhost.
             # These Systems are not supposed to send mail anywhere else
             # than our own domains.
-            'relayhost': '[mx0.kunbox.net]:2525',
+            'relayhost': '[rx300.kunbox.net]:2525',
         },
     },
 }
@@ -79,7 +79,7 @@ groups['home'] = {
             # It's fine to do this without authentificating to the relayhost.
             # These Systems are not supposed to send mail anywhere else
             # than our own domains.
-            'relayhost': '[mx0.kunbox.net]:2525',
+            'relayhost': '[rx300.kunbox.net]:2525',
         },
     },
 }
@@ -91,7 +91,7 @@ groups['ovh'] = {
     'metadata': {
         'location': 'ovh',
         'postfix': {
-            'relayhost': '[mx0.kunbox.net]:2525',
+            'relayhost': '[rx300.kunbox.net]:2525',
         },
         'users': {
             'debian': {