Let's say you've created a website for a small business and each staff member has his/her email account. A year later the business hires more employees and has its own sales and marketing department. The departments also have their own email addresses and they receive a lot of information on a daily basis. The process is repeated for other departments, such as PR.
What are several solutions available for keeping track of an increasing volume of emails? What should web developers do in this situation or what should they be aware of?
Right now I'm interested in the area of email submissions. I found a list of email marketing solutions in another part of the forums.