Inbound e-mails are those e-mails that are received and automatically create or update your defined processes. You can choose to send a response to an inbound e-mail to confirm if it was successful or not.
Outbound e-mails are those e-mails that are automatically sent in response to inbound e-mail, confirming the success of the inbound e-mail, or containing a requested status report. Outbound e-mail is also sent to notify the relevant people of reminders, assignments or escalations.
You can configure:
The e-mail profile that Mail uses, and where any attachments and reports are stored
How Mail handles e-mails that it cannot recognize
Which stages of the process are controlled by Mail