Lists work well to a certain extent but would not be suitable for a number of cases. Say a team member decides to add an existing email conversation to the list at a later point in time. This would break the original email thread structure when added to list. What happens to an email in a conversation which came from someone outside the company. Someone forwards it to list again? Say someone forgets to do a "reply all" in an ongoing conversation, this email never lands up in the list.

We like using email for most of our tasks too. We use our own product GrexIt's (http://grexit.com) Shared Labels to share information and even collaborate right from our email inbox. Shared labels allow you to share particular Gmail label among a group of people in your company. Every email conversation on which a shared label is applied gets pushed to the user's inbox who were part of the shared label. All followup emails that arrive in an ongoing conversation also keep getting shared automatically. This approach requires minimal effort to share information and works better than lists. Most importantly users continue to access information from their inbox itself.

We use the shared labels approach for a variety of use cases like support and development. As soon as support email arrives to the support@ email-id it get shared with everyone. We have shared labels with every team member's name, say Task:John. To assign an email to someone, we simply apply the user's shared label on that email. This allows us to collaborate easily without needing any 3rd party tools