diff --git a/frontend/src/components/mail/MailGroupPanel.tsx b/frontend/src/components/mail/MailGroupPanel.tsx
index b7d0b4f..cc7698a 100644
--- a/frontend/src/components/mail/MailGroupPanel.tsx
+++ b/frontend/src/components/mail/MailGroupPanel.tsx
@@ -68,11 +68,11 @@ export function applyGrouping(mails: any[], groupState: GroupState): GroupedMail
     const sortedKeys = Array.from(subGroups.keys()).sort();
     return sortedKeys.map((key) => {
       const groupMails = subGroups.get(key)!;
-      const subGroups = groupRecursive(groupMails, conditions, depth + 1);
-      if (subGroups.length === 1 && subGroups[0].key === 'all') {
+      const childGroups = groupRecursive(groupMails, conditions, depth + 1);
+      if (childGroups.length === 1 && childGroups[0].key === 'all') {
         return { key, label: key, mails: groupMails };
       }
-      return { key, label: key, mails: [], subGroups };
+      return { key, label: key, mails: [], subGroups: childGroups };
     });
   }