def failed(resource_export_file)
    @resource_export_file = resource_export_file
    @library_group = LibraryGroup.site_config
    from = "#{LibraryGroup.system_name(resource_export_file.user.profile.locale)} <#{@library_group.email}>"
    subject = "#{I18n.t('resource_export_mailer.failed.subject')}: #{@resource_export_file.id}"