1. Go to Settings > Messages > Encryption.
![turn on openpgp digital signing for all outgoing mails](https://kb.mailfence.com/wp-content/uploads/2022/03/turn-on-openpgp-digital-signing-for-all-outgoing-mails-1-e1682418105606.jpeg)
2. Tick the box Sign all my emails with my personal key.
![turn on openpgp digital signing for all outgoing mails](https://kb.mailfence.com/wp-content/uploads/2022/03/turn-on-openpgp-digital-signing-for-all-outgoing-mails-3.jpeg)
The recipient will need to have your OpenPGP public key to be able to validate your digital signature. You can share your OpenPGP public key by email.