These best practices and white papers represent the cooperative efforts of M3AAWG members to provide the industry with recommendations and background information to improve messaging security and protect users. M3AAWG best practices are updated as needed and new documents are added as they become available.
With the advent of International Domain Names, Internationalized Top-Level Domains and Email Address Internationalization there will be an increase in the legitimate usage of Unicode characters and an increase in the potential for its abuse as well. This document provides best practices to curtail the potential Unicode abuse.
Provides background on the use of Unicode characters in the abuse context with a tutorial on the options to curtail that abuse.
Opportunistic encryption is one step in protecting email traffic between messaging providers but it might not be sufficient unless forward secrecy is also employed for the connection. This document explains why forward secrecy is necessary and provides guidance for implementing it.
Many organizations and individuals register “parked” domains not meant to either send or receive email traffic. Mailbox providers can authenticate incoming email from these domains quite effectively, provided such domains have the necessary identifiers. This best practices document describes what identifiers can be used to indicate a domain or subdomain that is not meant to send or receive emails. The December 2015 version updates some industry links that changed.
Even though opportunistic encryption protects messages during transmission from sender to receiver, it is still possible for a Man-in-the-Middle (MITM) attacker with a self-signed certificate to impersonate the intended destination. This brief document describes the MITM situation, outlines various methods bad actors can use to conduct MITM attacks, covers components for deterring these attacks and introduces DANE (DNS-based Authentication of Named Entities), a new technology to assist messaging providers in validating they are communicating with an intended destination when using SSL/TLS.