diff --git a/systems/x86_64-linux/prefect/services/mailserver/default.nix b/systems/x86_64-linux/prefect/services/mailserver/default.nix
index 8388ec96..591a9a44 100644
--- a/systems/x86_64-linux/prefect/services/mailserver/default.nix
+++ b/systems/x86_64-linux/prefect/services/mailserver/default.nix
@@ -103,7 +103,7 @@
       wantedBy = [ "timers.target" ];
       timerConfig = {
         OnBootSec = "5m";
-        OnCalendar = "monthly";
+        OnCalendar = "daily";
         Unit = "copy-mail-certs.service";
       };
     };