Backslash and the KU Domain
For some browsers and countries outside of the UK it may be necessary to prefix your username with "KUDS\" (e.g. KUDS\K0123456...

If you cannot find the backslash character (on UK keyboards it is to the left of the "z" key) then you should be able to get it by holding down the ALT key and tapping 92 on the numeric keypad. Or simply copy the domain name and backslash from below and paste it into the Username field in Outlook for Web
KUDS\