What are the main features of a comprehensive customer relationship management (CRM) system? Your response should contain at least 4 bullet points. Use the markdown bullet points such as: * This is point 1. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. In your response, the word "features" should appear at least 2 times. P.S. Let me know if you have any questions.

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