Is it appropriate to e-mail a thank you to a prospective employer after an interview?

I've always sent a written thank you note after an interview but was wondering it is appropriate to send an e-mail thank you.

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia��).