Use any() instead of create one script because the builtin function does the same thing

bt5/erp5_crm/PropertySheetTemplateItem/portal_property_sheets/EventConstraint/destination_email_constraint.xml

@@ -20,11 +20,14 @@
         </item>
         <item>
             <key> <string>description</string> </key>
-            <value> <string>Recipients email must be defined</string> </value>
+            <value> <string>Recipients email must be defined\n
+\n
+\n
+python: object.getDestination() is not None and any(destination for destination in context.getDestinationValueList() if not destination.getDefaultEmailText())</string> </value>
         </item>
         <item>
             <key> <string>expression</string> </key>
-            <value> <string>python: object.getDestination() is not None and object.Event_checkIfDestinationEmailExist()</string> </value>
+            <value> <string>python: object.getDestination() is not None and any(destination for destination in context.getDestinationValueList() if not destination.getDefaultEmailText())</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>

bt5/erp5_crm/SkinTemplateItem/portal_skins/erp5_crm/Event_checkIfDestinationEmailExist.xml

-<?xml version="1.0"?>
-<ZopeData>
-  <record id="1" aka="AAAAAAAAAAE=">
-    <pickle>
-      <global name="PythonScript" module="Products.PythonScripts.PythonScript"/>
-    </pickle>
-    <pickle>
-      <dictionary>
-        <item>
-            <key> <string>Script_magic</string> </key>
-            <value> <int>3</int> </value>
-        </item>
-        <item>
-            <key> <string>_bind_names</string> </key>
-            <value>
-              <object>
-                <klass>
-                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
-                </klass>
-                <tuple/>
-                <state>
-                  <dictionary>
-                    <item>
-                        <key> <string>_asgns</string> </key>
-                        <value>
-                          <dictionary>
-                            <item>
-                                <key> <string>name_container</string> </key>
-                                <value> <string>container</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_context</string> </key>
-                                <value> <string>context</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_m_self</string> </key>
-                                <value> <string>script</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_subpath</string> </key>
-                                <value> <string>traverse_subpath</string> </value>
-                            </item>
-                          </dictionary>
-                        </value>
-                    </item>
-                  </dictionary>
-                </state>
-              </object>
-            </value>
-        </item>
-        <item>
-            <key> <string>_body</string> </key>
-            <value> <string>destination_list = context.getDestinationValueList()\n
-for destination in destination_list:\n
-  if destination.getDefaultEmailText() in (None, \'\'):\n
-    return False\n
-\n
-return True\n
-</string> </value>
-        </item>
-        <item>
-            <key> <string>_params</string> </key>
-            <value> <string></string> </value>
-        </item>
-        <item>
-            <key> <string>id</string> </key>
-            <value> <string>Event_checkIfDestinationEmailExist</string> </value>
-        </item>
-      </dictionary>
-    </pickle>
-  </record>
-</ZopeData>

bt5/erp5_crm/bt/revision

-643
+644
\ No newline at end of file