diff --git a/conf/postgrey_whitelist_clients b/conf/postgrey_whitelist_clients
index 9f7eef4b..c2ad2c82 100644
--- a/conf/postgrey_whitelist_clients
+++ b/conf/postgrey_whitelist_clients
@@ -14,3 +14,5 @@
 /^o\d+\.email\.londontrustmedia.com$/
 /^o\d+\.support\.privateinternetaccess.com$/
 /^o\d+\.outbound-mail\.sendgrid.net$/
+/^box.kroes.email$/
+/^.*.hes.trendmicro.eu$/