Awesome Email Security

A curated list of awesome resources related to enhancing your enterprise Email Security. Learn about email security protocols and best practices. Contributions are welcome!

Contents

• Email Authentication
• Email Filtering
• Email Encryption
• Phishing Protection
• Tools
• Reading

Email Authentication

SPF (Sender Policy Framework)

• SPF Introduction - SPF Explanation by PowerDMARC.
• SPF Introduction Dmarcian - SPF Explanation by Dmarcian.
• SPF Record Setup - SPF Record Setup by PowerDMARC.
• SPF Macros - SPF Macro Explanation.

DKIM (DomainKeys Identified Mail)

• DKIM Technical Details - Technical Deep Dive on DKIM.
• DKIM Record Configuration - Configuring a DKIM record.

DMARC (Domain-based Message Authentication, Reporting, and Conformance)

• DMARC Introduction - An introductory explanation of DMARC and how it works.
• DMARC Explanation - Good DMARC alignment explanation.

BIMI (Brand Indicators for Message Identification)

• BIMI Complete Guide - BIMI Introduction and Compelete guide.
• BIMI Implementation Guide - BIMI Group Implementation guide.

MTA-STS (Mail Transfer Agent Strict Transport Security)

• MTA-STS Introduction and Implementation - A guide on MTA-STS by PowerDMARC.

Email Filtering

Anti-Spam Solutions

• Email Filtering concepts - Introduction to email filtering concepts and different types of spam filtering.
• Exchange Online Email Filtering - Exchange online email filtering details.

File Extensions Filtering

• List of File Extensions to Block - A list of file extensions to block depending on your policy.

Email Encryption

Transport Layer Security (TLS) for Email Transport

• STARTTLS - An Explainer for STARTTLS and Opportunistic TLS vs Forced TLS.
• Email Transport Encryption Protocols - Explains the difference between STARTTLS, DANE, MTA-STS.

S/MIME Secure – Multipurpose Internet Mail Extensions

• S/MIME Introduction - S/MIME Introduction.

Open PGP Open Pretty Good Privacy

• Introduction to Open PGP - Open PGP Intro.

GPG GNU Privacy Guard

Phishing Protection

Email Content Analysis for Phishing Detection

• Sublime Rules - Sublime Security Open Source Detection Rules.
• Phishing Detection Keywords - Phishing Detection Keywords to check for.

Tools

Email Header Analysis

• Microsoft MHA - Microsoft Email Header Analysis.
• MxToolBox MHA - MxToolBox Email Header Analyzer.
• CyberDefenders MHA - Excellent Email Header Analyzer that can be deployed locally.

DMARC Reports Analysis

• MxToolBox DMARC Report Analyzer - MxToolBox DMARC Report Analyzer.
• Open Source DMARC Report Analyzer - Open Source DMARC Report Analyzer.

Commercial Email Security Tools

Open Source Email Security Tools

• DMARC Record Analyzer - CISA SPF/DMARC Record Analyzer.
• DMARC Report Parser - DMARC Report Parser.
• DMARC Report Parser - ThePhish is an automated phishing email analysis tool based on TheHive, Cortex and MISP.

Reading

Books

• Email Security: Attack and Defence - A book on Email Security.