The Sent Campaign report provides plenty of statistics regarding your email campaigns. Here are some definitions of these metrics:
Open: recipient has opened email
Clicks: recipient has clicked on a link in email
Downloads: recipient has download content from email – this only applies to emails with attachments (the attachment would need to be attached to the email via itracMarketer email campaign process)
Activity: recipient has linked to web from email, ie., if there is a link in the email that goes to a website that has itrac tracking code, it will show how much web activity was generated by the email campaign