PoliteMail, like all email marketing software, uses standard web-page image tracking to determine opens. Therefore, email open tracking is actually a result of the recipient displaying the images within the email. It is the image referenced from the PoliteMail Server that enables measurement of the open, and no other user interaction is required (unlike a read-receipt, which interrupts the user and requires input).
If you don’t include images within the email, PoliteMail will include a tiny transparent tracking image (sometimes called a web beacon). Images are displayed automatically when the sender’s address is in the recipient’s address book, contacts, or safe senders list. Otherwise, the recipient must click the download pictures or display contact bar at the top of the email message.
For internal email in corporate environments, Exchange administrators can set group policies to automatically download pictures when email is from internal addresses, providing PoliteMail users with significantly more accurate open tracking results.
Link tracking will always tell you who clicks on a specific link and when. Link clicks are tracked using tracking codes, which only display when hovering over the link within the email (just like the links within an email from Amazon.com, for example). This is the only difference your recipients would notice between a PoliteMail message and a regular Outlook email.