Thank you, both.
BOAC - might work, but how does one find ANY Outlook Express properties?? I have trawled through all the (to me) obvious areas but can find nothing which would allow me to modify or delete the account.
GG - Nothing in the Tools menu which gives that sequence.
Possible extra problem in that the OS is Win ME (yuck!!) and that Tiscali have their own, idiosynchratic, mail set-up ... not like any other version I've come across.