diff --git a/dashboard/src/components/MailboxDialog.vue b/dashboard/src/components/MailboxDialog.vue
index a09479701..c718fe976 100644
--- a/dashboard/src/components/MailboxDialog.vue
+++ b/dashboard/src/components/MailboxDialog.vue
@@ -88,7 +88,7 @@ async function onSubmit() {
     }
   }
 
-  emit('success');
+  emit('success', { domain: domain.value, name: name.value, fullName: name.value + '@' + domain.value });
   dialog.value.close();
   busy.value = false;
 }
diff --git a/dashboard/src/views/EmailMailboxesView.vue b/dashboard/src/views/EmailMailboxesView.vue
index 89a08f3c6..0b45c850e 100644
--- a/dashboard/src/views/EmailMailboxesView.vue
+++ b/dashboard/src/views/EmailMailboxesView.vue
@@ -108,7 +108,7 @@ const filteredMailboxes = computed(() => {
 });
 
 const filteredMailboxesUsage = computed(() => {
-  return filteredMailboxes.value.reduce((acc, m) => acc + (m.usage && m.usage.diskSize), 0);
+  return filteredMailboxes.value.reduce((acc, m) => acc + (cachedMailboxUsage.value[m.fullName] && cachedMailboxUsage.value[m.fullName].diskSize), 0);
 });
 
 const mailboxDialog = useTemplateRef('mailboxDialog');
@@ -144,59 +144,68 @@ async function onSubmitRemove() {
     return console.error(error);
   }
 
-  await refresh();
+  const idx = mailboxes.value.findIndex(mbox => mbox.fullName === removeMailbox.value.fullName);
+  if (idx !== -1) mailboxes.value.splice(idx, 1);
+
   removeDialog.value.close();
 
   removeBusy.value = false;
 }
 
+const cachedMailboxUsage = ref({});
+
+async function refreshDomainUsage(domain) {
+  const [error, usage] = await mailModel.usage(domain);
+  // retry if mail addon cannot be reached during restarts
+  if (error && error.status === 424) return setTimeout(refresh, 2000);
+  else if (error) return console.error(error);
+
+  mailboxes.value.forEach((m) => {
+    if (usage[m.fullName]) cachedMailboxUsage.value[m.fullName] = usage[m.fullName];
+  });
+
+  mailboxesUsage.value = mailboxes.value.reduce((acc, m) => acc + (cachedMailboxUsage.value[m.fullName] && cachedMailboxUsage.value[m.fullName].diskSize), 0);
+}
+
 async function refreshUsage() {
-  async function refreshForDomain(domain) {
-    const [error, usage] = await mailModel.usage(domain);
-    // retry if mail addon cannot be reached during restarts
-    if (error && error.status === 424) return setTimeout(refresh, 2000);
-    else if (error) return console.error(error);
-
-    mailboxes.value.forEach((m) => {
-      m.usage = usage[m.fullName] ?? { diskSize: 0}; // can be missing from response if no email has been received by dovecot
-    });
-  }
-
   try {
-    await eachLimit(domains.value.map(d => d.domain), 10, refreshForDomain);
+    await eachLimit(domains.value.map(d => d.domain), 10, refreshDomainUsage);
   } catch (error) {
     return console.error(error);
   }
+}
 
-  mailboxesUsage.value = mailboxes.value.reduce((acc, m) => acc + (m.usage && m.usage.diskSize), 0);
+async function refreshDomain(domain) {
+  const [error, result] = await mailboxesModel.list(domain);
+  if (error) throw error;
+
+  result.forEach((m) => {
+    m.fullName = m.name + '@' + m.domain;
+
+    m.owner = users.value.find(u => u.id === m.ownerId) || null;
+    if (!m.owner) m.owner = groups.value.find(g => g.id === m.ownerId) || null;
+
+    m.ownerDisplayName = m.owner ? (m.owner.username || m.owner.name) : '';
+    cachedMailboxUsage.value[m.fullName] = cachedMailboxUsage.value[m.fullName] || { diskSize: 0 };
+
+    // update in-place or add
+    const idx = mailboxes.value.findIndex(mbox => mbox.fullName === m.fullName);
+    if (idx !== -1) mailboxes.value[idx] = m;
+    else mailboxes.value.push(m);
+  });
 }
 
 async function refresh() {
-  let tmp = [];
-  async function refreshForDomain(domain) {
-    const [error, result] = await mailboxesModel.list(domain);
-    if (error) throw error;
-
-    result.forEach((m) => {
-      m.fullName = m.name + '@' + m.domain;
-
-      m.owner = users.value.find(u => u.id === m.ownerId) || null;
-      if (!m.owner) m.owner = groups.value.find(g => g.id === m.ownerId) || null;
-
-      m.ownerDisplayName = m.owner ? (m.owner.username || m.owner.name) : '';
-      m.usage = -1;
-    });
-
-    tmp = tmp.concat(result);
-  }
-
   try {
-    await eachLimit(domains.value.map(d => d.domain), 10, refreshForDomain);
+    await eachLimit(domains.value.map(d => d.domain), 10, refreshDomain);
   } catch (error) {
     return console.error(error);
   }
+}
 
-  mailboxes.value = tmp;
+async function onMailboxDialogSuccess(mailbox) {
+  await refreshDomain(mailbox.domain);
+  await refreshDomainUsage(mailbox.domain);
 }
 
 onMounted(async () => {
@@ -250,7 +259,7 @@ onMounted(async () => {
       </div>
     </Dialog>
 
-    <MailboxDialog ref="mailboxDialog" :apps="apps" :users="users" :groups="groups" :domains="domains" @success="refresh()"/>
+    <MailboxDialog ref="mailboxDialog" :apps="apps" :users="users" :groups="groups" :domains="domains" @success="onMailboxDialogSuccess"/>
 
     <Section :title="$t('email.incoming.mailboxes.title')">
       <template #header-title-extra>
@@ -264,11 +273,11 @@ onMounted(async () => {
       <TableView :columns="columns" :model="filteredMailboxes" :busy="busy" :fixed-layout="true" :placeholder="$t(searchFilter ? 'email.incoming.mailboxes.noMatchesPlaceholder' : 'email.incoming.mailboxes.emptyPlaceholder')">
         <template #aliases="mailbox">{{ mailbox.aliases.length }}</template>
         <template #usage="mailbox">
-          <span v-if="mailbox.usage !== -1">{{ prettyDecimalSize(mailbox.usage.diskSize) }}</span>
+          <span v-if="cachedMailboxUsage[mailbox.fullName]">{{ prettyDecimalSize(cachedMailboxUsage[mailbox.fullName].diskSize) }}</span>
           <span v-else>{{ $t('main.loadingPlaceholder') }} ...</span>
         </template>
         <template #storageQuota="mailbox">
-          <span v-if="mailbox.usage && mailbox.usage.quotaLimit">{{ prettyDecimalSize(mailbox.usage.quotaLimit) }}</span>
+          <span v-if="cachedMailboxUsage[mailbox.fullName] && typeof cachedMailboxUsage[mailbox.fullName].quotaLimit !== 'undefined'">{{ prettyDecimalSize(cachedMailboxUsage[mailbox.fullName].quotaLimit) }}</span>
           <span v-else>-</span>
         </template>
         <template #actions="mailbox">