e-mail attachments and security

[mailing at vankets.com (Bert Van Kets)]

Hi Guys,

I got a pretty interesting question from my brother yesterday. He's a
medical doctor in the UK and he needs to send reports to other doctors
by e-mail regularly. The reports are in MS Word format. These doctors
are in different locations and not connected to a common organization
(hospital or company).
At the moment he uses the MSWord password protection to try to keep the
sensitive data away from prying eyes. We all know how secure that method
is (not!).
I told hem he'd better use some other system that guarantees a bit more
protection but the problem is he can not ask of the people who receive
the reports to install extra software (like PGP or GPG encryption). The
security may not get in the way of the usability. Asking the receivers
to install extra software and configuring it is not an option. These are
not IT guys and don't even know how to spell GPG, let alone install it.
Passing a password over by telephone is the maximum these guys are
willing to go. 8-O

Do you guys have some ideas on what could be a better solution for this
"three legged stool" problem?

Thanks.

Bert