I can assure you that most IT staff in the NHS would love to have got rid of IE6 years ago! Unfortunately, when they were told it was able to move at the start of this year, that is just the beginning of the process. Things have to be tested.
As for NHS.net, remember this is webmail and can be read on any computer in the country - not just those nice secure NHS ones! Sending it from one NHS.net account to another is secure but since someone can read it on their home PCs or one in a public library you have to wonder how secure it is.