diff --git a/postgrey_whitelist_clients b/postgrey_whitelist_clients
index aa3e2dc..04eed3e 100644
--- a/postgrey_whitelist_clients
+++ b/postgrey_whitelist_clients
@@ -307,4 +307,8 @@ dhosting.com
 cloudflare.net
 me.com
 mimecast.com
-sparkpostmail.com
\ No newline at end of file
+sparkpostmail.com
+# 2025-06-03 (address verfication, multi-factor authentication, downtime alerts, etc.)
+.*\.inter-corporate\.(ca|com|net)$/
+.*\.lumbercartel\.ca$/
+.*\.openspf\.ca$/