diff --git a/cmdeploy/src/cmdeploy/filtermail/filtermail-transport.service.j2 b/cmdeploy/src/cmdeploy/filtermail/filtermail-transport.service.j2
index ccb4f98f..7e615908 100644
--- a/cmdeploy/src/cmdeploy/filtermail/filtermail-transport.service.j2
+++ b/cmdeploy/src/cmdeploy/filtermail/filtermail-transport.service.j2
@@ -6,6 +6,7 @@ ExecStart={{ bin_path }} {{ config_path }} transport
 Restart=always
 RestartSec=30
 User=vmail
+LimitNOFILE=524288
 
 [Install]
 WantedBy=multi-user.target