IndexError: list index out of range for email.split

Getting IndexError: list index out of range when trying to send email manually(create new email in communication) or selecting email address not linked to a customer when sending sales invoice.
below is the traceback
OS: Ubuntu 20.04
erpnext: 13.21.0
frappe: 13.21.0
happened since adding email domain and new email account

  File "apps/frappe/frappe/", line 68, in application
    response = frappe.api.handle()
  File "apps/frappe/frappe/", line 55, in handle
    return frappe.handler.handle()
  File "apps/frappe/frappe/", line 31, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/", line 68, in execute_cmd
    return, **frappe.form_dict)
  File "apps/frappe/frappe/", line 1213, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/core/doctype/communication/", line 58, in make
    comm = frappe.get_doc({
  File "apps/frappe/frappe/model/", line 240, in insert
  File "apps/frappe/frappe/model/", line 971, in run_before_save_methods
  File "apps/frappe/frappe/model/", line 869, in run_method
    out = Document.hook(fn)(self, *args, **kwargs)
  File "apps/frappe/frappe/model/", line 1161, in composer
    return composed(self, method, *args, **kwargs)
  File "apps/frappe/frappe/model/", line 1144, in runner
    add_to_return_value(self, fn(self, *args, **kwargs))
  File "apps/frappe/frappe/model/", line 863, in <lambda>
    fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
  File "apps/frappe/frappe/core/doctype/communication/", line 66, in validate
  File "apps/frappe/frappe/core/doctype/communication/", line 263, in set_timeline_links
    contacts = get_contacts([self.sender, self.recipients,, self.bcc], auto_create_contact=create_contact_enabled)
  File "apps/frappe/frappe/core/doctype/communication/", line 353, in get_contacts
    email = get_email_without_link(email)
  File "apps/frappe/frappe/core/doctype/communication/", line 425, in get_email_without_link
    email_host = email.split("@")[1]
IndexError: list index out of range

This was fixed in 13.22 fix: add try except for splitting email by hrwX · Pull Request #15892 · frappe/frappe · GitHub