taskbar logo

Hi all,      I seem to have lost the email logo that used to reside on the taskbar on my PC. This means I can no longer see any notifications of new email in my NTLworld address. I get them on my phone no problem but not on my PC. I get the ' outlook '  logo on the taskbar complete with notifications of new mail.    I can't find any reference to email other than outlook.  How can I replace the missing email logo ?       cheers