If you need to contact me, do so at the following address:
r e s e a r c h AT m a t t h e w n i e m e r g . c o m .
You'll probably want my GPG key.
Also, see my disclaimer on I posted on the home page. The way around this is to acknowledge in the email that the message is not encrypted or signed, and that you will do so in the future.
Many how-to guides exist on how to properly do this, regardless of your operating system.