Install your Certificate
1. Launch Lotus Notes.
2. Choose Files > Tools > User ID.
3. Go to the Certificates panel.
4. Scroll down in the Certificates Issued By list until you see the new certificates you just imported.
5. Select your public key certificate.
6. Make sure that This is your default signing certificate is checked.
7. Click OK.
Sign and Encrypt your email messages
1. When composing an e-mail message, click the Delivery Options action button.
2. In the Basics tab, select Sign (to digitally sign your emails) or Encrypt (to encrypt your emails) or both.
3. Click OK.