This document specifies the Internet Message Format (IMF), a syntax for text messages that are sent between computer users, within the framework of "electronic mail" messages. This specification is a revision of Request For Comments (RFC) 2822, which itself superseded Request For Comments (RFC) 822, "Standard for the Format of ARPA Internet Text Messages", updating it to reflect current practice and incorporating incremental changes that were specified in other RFCs. [STANDARDS-TRACK]| IETF Datatracker
Internet mail determines the address of a receiving server through the DNS, first by looking for an MX record and then by looking for an A/AAAA record as a fallback. Unfortunately, this means that the A/AAAA record is taken to be mail server address even when that address does not accept mail. The No Service MX RR, informally called "null MX", formalizes the existing mechanism by which a domain announces that it accepts no mail, without having to provide a mail server; this permits significan...| IETF Datatracker
SMTP MTA Strict Transport Security (MTA-STS) is a mechanism enabling mail service providers (SPs) to declare their ability to receive Transport Layer Security (TLS) secure SMTP connections and to specify whether sending SMTP servers should refuse to deliver to MX hosts that do not offer TLS with a trusted server certificate.| IETF Datatracker
So, you want to talk to your SMTP email server and send emails? Let’s go through SMTP and ESMTP basics, some SMTP commands, and SMTP server response codes.| Mailgun
First defined in 1998, the iCalendar standard remains ubiquitous in enterprise software. However, it did not account for modern security concerns and allowed vendors to create proprietary extensions that expanded the format’s attack surface. I demonstrate how flawed RFC implementations led to vulnerabilities in popular enterprise applications. Attackers can trigger exploits remotely with zero user interaction due to automatic parsing of event invitations. Furthermore, I explain how iCalenda...| spaceraccoon.dev
Introduction to TLS v1.2| www.gabriel.urdhr.fr
A number of protocols exist for establishing encrypted channels between SMTP Mail Transfer Agents (MTAs), including STARTTLS, DNS- Based Authentication of Named Entities (DANE) TLSA, and MTA Strict Transport Security (MTA-STS). These protocols can fail due to misconfiguration or active attack, leading to undelivered messages or delivery over unencrypted or unauthenticated channels. This document describes a reporting mechanism and format by which sending systems can share statistics and speci...| IETF Datatracker
Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a scalable mechanism by which a mail-originating organization can express domain-level policies and preferences for message validation, disposition, and reporting, that a mail-receiving organization can use to improve mail handling. Originators of Internet Mail need to be able to associate reliable and authenticated domain identifiers with messages, communicate policies about messages that use those identifiers, and re...| IETF Datatracker
This memo describes a downgrade-resistant protocol for SMTP transport security between Message Transfer Agents (MTAs), based on the DNS-Based Authentication of Named Entities (DANE) TLSA DNS record. Adoption of this protocol enables an incremental transition of the Internet email backbone to one using encrypted and authenticated Transport Layer Security (TLS).| IETF Datatracker
DomainKeys Identified Mail (DKIM) permits a person, role, or organization that owns the signing domain to claim some responsibility for a message by associating the domain with the message. This can be an author's organization, an operational relay, or one of their agents. DKIM separates the question of the identity of the Signer of the message from the purported author of the message. Assertion of responsibility is validated through a cryptographic signature and by querying the Signer's doma...| IETF Datatracker
In the world of email security, a recent concern has arisen known as SMTP Smuggling, a vulnerability that can be exploited to spoof emails. This blog post will explain what SMTP smuggling is and how Stalwart Mail Server is designed to be immune to this vulnerability. We'll also discuss a new feature we've implemented to protect other servers that might be vulnerable.| stalw.art
Google and Yahoo announce new email authentication requirements for mass email senders to take email fraud prevention to the next level in 2024.| PowerDMARC
This document is a specification of the basic protocol for Internet electronic mail transport. It consolidates, updates, and clarifies several previous documents, making all or parts of most of them obsolete. It covers the SMTP extension mechanisms and best practices for the contemporary Internet, but does not provide details about particular extensions. Although SMTP was designed as a mail transport and delivery protocol, this specification also contains information that is important to its ...| IETF Datatracker
The Extensible Messaging and Presence Protocol (XMPP) is an application profile of the Extensible Markup Language (XML) that enables the near-real-time exchange of structured yet extensible data between any two or more network entities. This document defines XMPP's core protocol methods: setup and teardown of XML streams, channel encryption, authentication, error handling, and communication primitives for messaging, network availability ("presence"), and request-response interactions. This do...| IETF Datatracker
Sender Best Practices for mail deliverability| senders.yahooinc.com
The WebSocket Protocol enables two-way communication between a client running untrusted code in a controlled environment to a remote host that has opted-in to communications from that code. The security model used for this is the origin-based security model commonly used by web browsers. The protocol consists of an opening handshake followed by basic message framing, layered over TCP. The goal of this technology is to provide a mechanism for browser-based applications that need two-way commun...| IETF Datatracker