- Include your PGP key.
I can't send you an encrypted response if you don't.- Verify my PGP key.
The only source you should trust is this website's page containing my PGP key. A key that originates from any other source may be that of an imposter.- Use a strong encryption standard.
Using a quantum-proof standard is best. We must work to stay informed on new developments in Cryptography - both new cryptography standards, and new attacks.- Don't use an email provider that spys on you. PLEASE!
If you're sending from a Google, Yahoo, Outlook, or similar address, don't get a false sense of security - everything you are typing as you compose your email is being sent back to a data-center, mostly used for tailored advertising. Example from Google's Privacy Policy