Auto archiving email

Auto archiving email

I thought that the default policy to archives files more than 3 months old would mean that my older emails would be auto-archived. However, when I view my archived files, there are only 4 emails there. In another email client, if I don't delete mail, it stays in my inbox for years, which is very helpful with my business. How do I make it so that ALL my old mail and sent mail don't get deleted, whether archived or otherwise?