The organization employs spam protection mechanisms at critical information system entry points (e.g., firewalls, electronic mail servers, remote-access servers) and at workstations, servers, or mobile computing devices on the network. The organization uses the spam protection mechanisms to detect and take appropriate action on unsolicited messages transported by electronic mail, electronic mail attachments, Internet accesses, or other common means. Consideration is given to using spam protection software products from multiple vendors (e.g., using one vendor for boundary devices and servers and another vendor for workstations). NIST Special Publication 800-45 provides guidance on electronic mail security.