St. Bartholomew’s Cathedral in Frankfurt, Germany (© AlxeyPnferov/Getty Images)

This document allows broader use of the "Expires" message header field for mail messages. Message creators can then indicate when a message expires, while recipients can use this information to handle an expired message differently.

Sandhill cranes, Bosque del Apache National Wildlife Refuge, New Mexico, USA (© Terry St.Louis/Getty Images)

Source Address Validation (SAV) is an important means to mitigate IP source address spoofing (RFC 2827). This document analyzes the gaps in current operational mechanisms for intra-domain SAV. It also identifies the properties that new intra-domain…