Please use encryption whenever possible if you would like to write me an e-mail or contact me otherwise. There are three good options to get in touch with me over an encrypted channel:
The easiest option to communicate with me using secure encryption is to use the decentralized, end-to-end encrypted Matrix messaging protocol through the open-source Riot messaging app. Riot is available for all desktop operating systems, web browsers, Android and iOS. You can find me on Matrix / Riot using my e-mail address or the account name “@titusstahl:matrix.org”. Read here why I recommend Matrix.
Riot also supports audio and video chat and thus is a good replacement for Skype (which openly spies on its users and is horribly insecure).
It is slightly more difficult to send me an encrypted e-mail. Please consult this excellent guide to email encryption, authored by the Free Software Foundation to find out how it works.
My PGP keys can be obtained here:
Worried about the authenticity of my keys? There are cryptographic proofs of my identity on keybase.io/titusstahl. I also am available for signing your PGP keys upon seeing two pieces of government issued photo ID.
If you have my mobile phone number, you can also reach me on Signal.