• Correct setup of the app Mail
• Correct integration of the certification authorities into the operating system.
• Valid digital user certificate integrated into the operating system.

• Settings → Mail → Accounts → <your account at JADE-HS>
• In the section “Exchange” tap on the account with your email address at Jade University.
• Advanced settings, section S/MIME
  • Sign
    • Sign: activated
    • Certificates: Here you should now see your digital user certificate (recognisable by your name)
  • Encrypt by default
    • Encrypt by default: deactivated
• Finish the configuration by tapping on “Done”.

The configuration is now complete and you can sign any e-mail. If you have the public key of your communication partner, you can also encrypt every e-mail.

• Tap the “New e-mail” icon in the Mail app and compose it.
• As soon as you click on “Send”, the e-mail is digitally signed and then sent.
• The communication partner sees the loop symbol as a sign of a digitally signed e-mail.

To encrypt an e-mail, you must first have the communication partner's public key. To do this, have your communication partner send you a digitally signed e-mail, for example, which is automatically added to your key ring.

• Tap the “New e-mail” icon in the Mail app and compose it.
• Before sending, decide whether the message is digitally encrypted:
  • Unencrypted: the lock next to the addressee appears crossed out in blue.
  • Encrypted: the lock next to the addressee appears in blue.
• As soon as you click on “Send”, the e-mail will be sent according to your selection.
• The communication partner will see the lock symbol as a sign of an encrypted e-mail.