diff --git a/dashboard/src/components/MailboxDialog.vue b/dashboard/src/components/MailboxDialog.vue
index 5c0798374..58a046d1e 100644
--- a/dashboard/src/components/MailboxDialog.vue
+++ b/dashboard/src/components/MailboxDialog.vue
@@ -21,7 +21,7 @@ const ownerId = ref('');
 const usersAndGroups = ref([]);
 const storageQuotaEnabled = ref(false);
 const storageQuotaTicks = [ 500*1000*1000, 5*1000*1000*1000, 15*1000*1000*1000, 50*1000*1000*1000, 100*1000*1000*1000 ];
-const storageQuota = ref(0);
+const storageQuota = ref(5*1000*1000*1000);
 const active = ref(false);
 const enablePop3 = ref(false);