Thank you Foggy.
I had explained the situation in my original question when I first registered. Sorry you were misled.
I personally have never used or even seen Thunderbird so have no idea why there is a problem with this. All I know is that she says it is so different....
I will be seeing her...
Foggy,
Have some faith in your fellow 'users'.
I am sending this question for my sister who has just had Thunderbird installed on her home computer.
I use Outlook and do not have a problem.
I'm just trying to help someone out....:(