Chapter 2. Techniques
- Table of Contents
- 2.1. SMTP Transaction Delays
- 2.2. DNS Checks
- 2.2.1. DNS Blacklists
- 2.2.2. DNS Integrity Check
- 2.3. SMTP checks
- 2.3.1. Hello (HELO/EHLO) checks
- 2.3.2. Sender Address Checks
- 2.3.3. Recipient Address Checks
- 2.4. Greylisting
- 2.4.1. How it works
- 2.4.2. Greylisting in Multiple Mail Exchangers
- 2.4.3. Results
- 2.5. Sender Authorization Schemes
- 2.5.1. Sender Policy Framework (SPF)
- 2.5.2. Microsoft Caller-ID for E-Mail
- 2.5.3. RMX++
- 2.6. Message data checks
- 2.6.1. Header checks
- 2.6.2. Junk Mail Signature Repositories
- 2.6.3. Binary garbage checks
- 2.6.4. MIME checks
- 2.6.5. File Attachment Check
- 2.6.6. Virus Scanners
- 2.6.7. Spam Scanners
- 2.7. Blocking Collateral Spam