Email and Memos (Chapter 9): Email (external, formal format with subject line), Memos (internal, concise, action-oriented). Email structure: Subject line (clear), greeting, body (organized in paragraphs), closing, signature. Memo structure: TO/FROM/DATE/SUBJECT, body, action items. Best practices: Professional tone, spell-check, clear purpose, appropriate formality level. For accountants, email/memo usage affects audit trails and compliance. Exam tip: Use appropriate tool for audience; maintain professional standards in all communication.