You can configure Microsoft Dynamics AX to automatically send email notifications to users when specific events occur. For example, Dynamics AX can send email notifications to users when documents are assigned to them for approval (as defined by a workflow), or when sales orders are canceled (as defined by an alert rule).
To configure email functionality in Microsoft Dynamics AX, you'll need to connect Dynamics AX to an SMTP mail server, enter an email address for each user, set up a batch to send the email messages, and create email templates for the specific features that you're using (such as workflows and alert rules).
For step-by-step instructions on how to set this up, see this topic on TechNet: Configure email functionality in Microsoft Dynamics AX.
For instructions about how to set up email and address settings for customer contacts, see Set up collections.