Read Receipts

Wikipedia

E-mail tracking is a method for monitoring the e-mail delivery to intended recipient. Most tracking technologies utilize some form of digitally time-stamped record to reveal the exact time and date that your e-mail was received or opened, as well the IP address of the recipient.

E-mail tracking is useful when the sender wants to know if the intended recipient actually received the e-mail, or if they clicked the links. However, due to the nature of the technology, e-mail tracking cannot be considered an absolutely accurate indicator that a message was opened or read by the recipient.

Most e-mail marketing software provides tracking features, sometimes in aggregate (e.g. click-through rate), and sometimes on an individual basis.

Read-receipts
Some e-mail applications, such as Microsoft Office Outlook, employ a read-receipt tracking mechanism. The sender selects the receipt request option prior to sending the message, and then upon sending, each recipient has the option of notifying the sender that the message was received and/or read by the recipient.

However, requesting a receipt does not guarantee that you will get one, for several reasons. Very few e-mail applications or services support read receipts, and users can generally disable the functionality if they so wish. Those that do support it arent necessarily compatible with or capable of recognizing requests from a different e-mail service or application. Generally read receipts are only useful within an organization where all employees/members are using the same email service and application.

Depending on the recipients mail client and settings, they may be forced to click a notification button before they can move on with their work. Even though it is an opt-in process, therefore, a recipient may consider it inconvenient, discourteous, or invasive.

Read receipts are sent back to your Inbox as e-mail messages. Additional technical information, such as who it is fro read more at » http://en.wikipedia.org/wiki/E-mail+tracking