OpenPGP
–Add Key button: create a new OpenPGP key or import an existing one.
–OpenPGP Key Manager button : manage OpenPGP keys in the application.
S/MIME
–Personal certificate for digital signing field: select an S/MIME certificate to sign messages.
–Personal certificate for encryption field: select an S/MIME certificate to send encrypted messages.
–Manage S/MIME Certificates button: manage S/MIME certificates added and embedded in the application.
–S/MIME Security Devices button: manage S/MIME security modules and devices added and embedded in the application.
–Generate and save a CSR file as button: select a local directory and file name for your CSR file, and answer the questions to set the algorithm and strength.
Default settings for sending messages
–Disable encryption for new messages option: disable encryption of emails to be sent.
–Enable encryption for new messages option: Enable encryption for emails you send.
–Sign unencrypted messages checkbox: add a digital signature to unencrypted messages.
Additional settings
–Attach my public key when adding an OpenPGP digital signature checkbox: attach the OpenPGP public key to the signed message.
–Send OpenPGP public key(s) in the email headers compatibility with Autocrypt checkbox.
–Encrypt the subject of OpenPGP messages checkbox: encrypt the message subject with the OpenPGP key.
–Store draft messages in encrypted format checkbox: encrypt draft messages.
–Preferred encryption technology options: select the encryption method: Select automatically based on available keys or certificates, Prefer OpenPGP, or Prefer S/MIME.