Linksys Extender Setup is the wireless internet solution for New Extender Setup and further you will know the steps to install the Wifi Extender Setup. Further, you’ll know how to configure and perform the installation. Bt Mail is totally optional free email service which comes with BT Broadband. When you register for BT Broadband, it will ask if you would like to use your BT Email address. One of the benefits of BT Mail is that you can create up to 10 additional email addresses for family and friends. It is 11 (eleven) in total number.