Technology - Internet 5 - Email

Synopsis

Email has become the single most important application on the Internet. We examine the operation of mail servers, SMTP, POP3 and IMAP protocols. Email is an inherently insecure system which is threatened by spam and malicious messages which intend to compromise security. We examine cryptographic techniques and several approaches to mail filtering and spam reduction.

Table of Contents

• 1. Synopsis
• 2. Email
  • 2.1 Clients and servers
    • 2.1.1 Office and ISP based servers
    • 2.1.2 Primary and backup server
    • 2.1.3 ‘From:’ is insecure
    • 2.1.4 Web based email clients
  • 2.2 Simple Mail Transport Protocol – SMTP
  • 2.3 Security limitations of SMTP
    • 2.3.1 Security of access to an email account
    • 2.3.2 Virus and Trojan Horse emails
    • 2.3.3 Anti-virus filtering
    • 2.3.4 Spam – unsolicited bulk email
    • 2.3.5 Responding to and reporting spammers
    • 2.3.6 Spam without a server
    • 2.3.7 Filtering on the user’s computer
    • 2.3.8 Rejecting spam at the mail server
    • 2.3.9 Filtering at the mail server
    • 2.3.10 Spam is a major threat to email
  • 2.4 Encryption for security and authentication
    • 2.4.1 Email encryption software
  • 2.5 Protocols for retrieving emails
    • 2.5.1 POP3
    • 2.5.2 IMAP4
    • 2.5.3 Costs and benefits for the ISP
  • 2.6 Attachments
  • 2.7 Operational guidelines and plain-text formats
    • 2.7.1 Format=flowed line length changes
    • 2.7.2 Problems with HTML email
  • 2.8 Email discussion lists
• 3. Related reports