Thanks Michel,
I was thinking that a password or OTP could be included in the email either in plain text or in an XML format.
The idea is that a piece of software on my blackberry which current detects my location (using the built-in GPS) has capacity to send an email to the ISY. I also have a SOFT Token on my BB, but a password in the email would also suffice. I have a RADIUS server at home which could authenticate the OTP from the ISY, obviously most people do not have this, so a simple password would also work.
Just nice to have...
Rgds jh