Let us consider that incoming and outgoing email servers are configured, as well as an alias (or email) domain. For this example, let us assume we have openerp.com as alias domain. I have configured my Sales Department sales team to use the alias. It has tde+sales-department@openerp.com as email address, as shown on the following figure.

Incoming emails on tde+sales-department@openerp.com will therefore create new leads. They will belong to the Sales Department sales team. By default, you also have a generic email address like sales@yourdomain creating leads that do not fall into a dedicated sales team.

Running the mail gateway, new leads are created as new emails have been sent to my sales team, 2 in my case. Being a follower of those leads, new messages are pushed to me, meaning I have unread messages. I therefore have a "2" counter near my 'Leads' menu entry. This counter is called needaction, because it says the number of documents that require your attention. This counter is based on leads that have unread messages. By clicking on the counter, I filter the search on Leads that have unread messages (note the filter in the search bar).

If I read a lead, its messages are also considered as read. This means that the messages are not visible anymore in your Inbox, but in your Archives mailbox. Filtering on unread messages will not show this lead anymore. However, you can set it back as unread using the 'Set back as unread' button that you can found on each message in OpenChatter, in the top-right action buttons.

The new messages on documents I follow are also pushed into my Inbox, as shown on the next figure. In my case, two leads have been created and have unread messages.

You can then manage your leads: discuss with the customer, convert them into opportunities, ... Using the kanban view of the opportunities, a counter tells you the number of opportunities that belong to each column. Even folded column have a counter. This allows to know whether there are opportunities in this column without having to open it.

If new messages are posted on opportunities you follow, you will have unread messages. Using the needaction counter in the menu, you will filter the opportunities to have only those having unread messages. Even folded column will tell you that you have opportunities that require an answer from you using the top-column counter.