diff --git a/core/admin/mailu/ui/templates/alias/create.html b/core/admin/mailu/ui/templates/alias/create.html
index 4b0ea3e2..2079d191 100644
--- a/core/admin/mailu/ui/templates/alias/create.html
+++ b/core/admin/mailu/ui/templates/alias/create.html
@@ -12,7 +12,7 @@
 {% call macros.card() %}
 <form class="form" method="post" role="form">
   {{ form.hidden_tag() }}
-  {{ macros.form_field(form.localpart, append='<span class="input-group-addon">@'+domain.name+'</span>') }}
+  {{ macros.form_field(form.localpart, append='<span class="input-group-text">@'+domain.name+'</span>') }}
   {{ macros.form_field(form.wildcard) }}
   {{ macros.form_field(form.destination, class_='mailselect') }}
   {{ macros.form_field(form.comment) }}
diff --git a/core/admin/mailu/ui/templates/client.html b/core/admin/mailu/ui/templates/client.html
index 1fdcb7cb..668621af 100644
--- a/core/admin/mailu/ui/templates/client.html
+++ b/core/admin/mailu/ui/templates/client.html
@@ -1,3 +1,5 @@
+<!--TODO add translations for: configure your client, Incoming mail and Outgoing mail-->
+
 {% extends "base.html" %}
 
 {% block title %}
diff --git a/core/admin/mailu/ui/templates/domain/create.html b/core/admin/mailu/ui/templates/domain/create.html
index d84159b1..3fdd262a 100644
--- a/core/admin/mailu/ui/templates/domain/create.html
+++ b/core/admin/mailu/ui/templates/domain/create.html
@@ -11,7 +11,7 @@
   {{ macros.form_field(form.name) }}
   {{ macros.form_fields((form.max_users, form.max_aliases)) }}
   {{ macros.form_field(form.max_quota_bytes, step=1000000000, max=50000000000,
-      prepend='<span class="input-group-addon"><span id="quota">'+((form.max_quota_bytes.data//1000000000).__str__() if form.max_quota_bytes.data else '∞')+'</span> GiB</span>',
+      prepend='<span class="input-group-text"><span id="quota">'+((form.max_quota_bytes.data//1000000000).__str__() if form.max_quota_bytes.data else '∞')+'</span> GiB</span>',
       oninput='$("#quota").text(this.value == 0  ? "∞" : this.value/1000000000);') }}
   {{ macros.form_field(form.signup_enabled) }}
   {{ macros.form_field(form.comment) }}
diff --git a/core/admin/mailu/ui/templates/domain/signup.html b/core/admin/mailu/ui/templates/domain/signup.html
index 77b7fec9..e9dbd75f 100644
--- a/core/admin/mailu/ui/templates/domain/signup.html
+++ b/core/admin/mailu/ui/templates/domain/signup.html
@@ -24,7 +24,7 @@
 
   {% call macros.card() %}
   {% if form.localpart %}
-  {{ macros.form_fields((form.localpart, form.name), append='<span class="input-group-addon">@</span>') }}
+  {{ macros.form_fields((form.localpart, form.name), append='<span class="input-group-text">@</span>') }}
   {{ macros.form_fields((form.pw, form.pw2)) }}
   {% else %}
   {{ macros.form_field(form.name) }}
diff --git a/core/admin/mailu/ui/templates/macros.html b/core/admin/mailu/ui/templates/macros.html
index 5acc5bed..a53d85c7 100644
--- a/core/admin/mailu/ui/templates/macros.html
+++ b/core/admin/mailu/ui/templates/macros.html
@@ -37,9 +37,10 @@
     {{ field.label if label else '' }}
   {% else %}
     {{ field.label if label else '' }}{{ form_field_errors(field) }}
-    {% if prepend or append %}<div class="input-group">{% endif %}
-      {{ prepend|safe }}{{ field(class_="form-control " + class_, **kwargs) }}{{ append|safe }}
-    {% if prepend or append %}</div>{% endif %}
+      {% if prepend %}<div class="input-group-prepend">{% endif %}
+      {% if append %}<div class="input-group-text">{% endif %}
+        {{ prepend|safe }}{{ field(class_="form-control " + class_, **kwargs) }}{{ append|safe }}
+      {% if prepend or append %}</div>{% endif %}
   {% endif %}
 {% endmacro %}
 
diff --git a/core/admin/mailu/ui/templates/user/create.html b/core/admin/mailu/ui/templates/user/create.html
index a28c7048..886cbb88 100644
--- a/core/admin/mailu/ui/templates/user/create.html
+++ b/core/admin/mailu/ui/templates/user/create.html
@@ -13,7 +13,7 @@
   {{ form.hidden_tag() }}
 
   {% call macros.card(_("General")) %}
-  {{ macros.form_field(form.localpart, append='<span class="input-group-addon">@'+domain.name+'</span>') }}
+  {{ macros.form_field(form.localpart, append='<span class="input-group-text">@'+domain.name+'</span>') }}
   {{ macros.form_fields((form.pw, form.pw2)) }}
   {{ macros.form_field(form.displayed_name) }}
   {{ macros.form_field(form.comment) }}
@@ -22,7 +22,7 @@
 
   {% call macros.card(_("Features and quotas"), theme="success") %}
   {{ macros.form_field(form.quota_bytes, step=1000000000, max=(max_quota_bytes or domain.max_quota_bytes or 50000000000),
-      prepend='<span class="input-group-addon"><span id="quota">'+((form.quota_bytes.data//1000000000).__str__() if form.quota_bytes.data else '∞')+'</span> GiB</span>',
+      prepend='<span class="input-group-text"><span id="quota">'+((form.quota_bytes.data//1000000000).__str__() if form.quota_bytes.data else '∞')+'</span> GiB</span>',
       oninput='$("#quota").text(this.value == 0  ? "∞" : this.value/1000000000);') }}
   {{ macros.form_field(form.enable_imap) }}
   {{ macros.form_field(form.enable_pop) }}
diff --git a/core/admin/mailu/ui/templates/user/settings.html b/core/admin/mailu/ui/templates/user/settings.html
index e58cc89a..9aa672ca 100644
--- a/core/admin/mailu/ui/templates/user/settings.html
+++ b/core/admin/mailu/ui/templates/user/settings.html
@@ -19,7 +19,7 @@
   {% call macros.card(title=_("Antispam")) %}
   {{ macros.form_field(form.spam_enabled) }}
   {{ macros.form_field(form.spam_threshold, step=1, max=100,
-      prepend='<span class="input-group-addon"><span id="threshold">'+form.spam_threshold.data.__str__()+'</span>&nbsp;/&nbsp;100</span>',
+      prepend='<span class="input-group-text"><span id="threshold">'+form.spam_threshold.data.__str__()+'</span>&nbsp;/&nbsp;100</span>',
       oninput='$("#threshold").text(this.value);') }}
   {% endcall %}
 
diff --git a/core/admin/mailu/ui/templates/user/signup.html b/core/admin/mailu/ui/templates/user/signup.html
index 2b20bde9..1157cfa3 100644
--- a/core/admin/mailu/ui/templates/user/signup.html
+++ b/core/admin/mailu/ui/templates/user/signup.html
@@ -12,7 +12,7 @@
 <form class="form" method="post" role="form">
   {{ form.hidden_tag() }}
   {% call macros.card() %}
-  {{ macros.form_field(form.localpart, append='<span class="input-group-addon">@'+domain.name+'</span>') }}
+  {{ macros.form_field(form.localpart, append='<span class="input-group-text">@'+domain.name+'</span>') }}
   {{ macros.form_fields((form.pw, form.pw2)) }}
   {% if form.captcha %}
     {{ macros.form_field(form.captcha) }}