diff --git a/global-functions b/global-functions
index 3f7a65e..a93b883 100644
--- a/global-functions
+++ b/global-functions
@@ -330,6 +330,11 @@
   :local AllDone true;
   :local QueueLen [ :len $EmailQueue ];
 
+  :if ([ /tool/e-mail/get last-status ] = "in-progress") do={
+    $LogPrintExit2 debug $0 ("Sending mail in currently in progress, not flushing.") false;
+    :return false;
+  }
+
   :if ([ $IsTimeSync ] = false) do={
     $LogPrintExit2 debug $0 ("Time is not synced, not flushing.") false;
     :return false;