This provides us with information about which browser and which operating system is being used, which IP address is currently accessing it, and also who the provider is. It is also used to detect if the e-mail has been read and whether the link integrated into the e-mail has been clicked on, such that the website has been visited from that IP address. Moreover, it is used to count the number of accesses to the website and the relevant time of day when the e-mail was opened and the access was performed.