diff --git a/lib/api/kolab_api_service_form_value.php b/lib/api/kolab_api_service_form_value.php
--- a/lib/api/kolab_api_service_form_value.php
+++ b/lib/api/kolab_api_service_form_value.php
@@ -1594,6 +1594,12 @@
         return $valid;
     }
 
+    /**
+     * Lists the valid domains given a primary domain name space.
+     *
+     * Includes the parent domain and any alias or child domains.
+     * Considers domains that point to the same base dn to be child domains.
+     */
     private function _get_valid_domains($my_primary_domain = null)
     {
         $my_primary_domain  = $my_primary_domain !== null
@@ -1604,10 +1610,11 @@
         $conf          = Conf::get_instance();
         $all_domains   = $auth->list_domains();
         $all_domains   = $all_domains['list'];
+        $all_basedns   = Array();
         $dna           = $conf->get('domain_name_attribute');
+        $dra           = $conf->get('domain_rootdn_attribute');
 
-        Log::trace("__get_valid_domains( " . $my_primary_domain . ")");
-        Log::trace("\$all_domains includes: " . var_export($all_domains, TRUE) . " (must include domain for \$my_primary_domain)");
+        Log::trace("_get_valid_domains(" . $my_primary_domain . ")");
 
         $valid_domains = $my_primary_domain ? array($my_primary_domain) : array();
         foreach ($all_domains as $domain_id => $domain_attrs) {
@@ -1618,9 +1625,27 @@
             if (in_array($my_primary_domain, $domain_attrs[$dna])) {
                 $valid_domains = array_merge($valid_domains, $domain_attrs[$dna]);
             }
+
+            if (array_key_exists($dra, $domain_attrs)) {
+                if (array_key_exists($domain_attrs[$dra], $all_basedns)) {
+                    $all_basedns[$domain_attrs[$dra]] = array_merge($all_basedns[$domain_attrs[$dra]], $domain_attrs[$dna]);
+                } else {
+                    $all_basedns[$domain_attrs[$dra]] = $domain_attrs[$dna];
+                }
+            }
         }
 
-        return array_unique($valid_domains);
+        foreach ($all_basedns as $base_dn => $domains) {
+            if (in_array($my_primary_domain, $domains)) {
+                $valid_domains = array_merge($valid_domains, $domains);
+            }
+        }
+
+        $result = array_unique($valid_domains);
+
+        Log::trace("_get_valid_domains result: " . var_export($result, TRUE));
+
+        return array_unique($result);
     }
 
     private function _validate_email_address_in_any_of_my_domains($mail_address)