I am referring to the reported bug https://bugs.kde.org/show_bug.cgi?id=297956 for KOrganizer. The signing of mails is set on standard for every outgoing mail in KMail. Unfortunately this doesn't include invites send out by the calendar in Kontact. It would be a nice feature and a good thing to generally enhance security. Encryption doesn't work and should be a feature as well. Reproducible: Always Steps to Reproduce: 1. Create an appointment 2. Send out the automatic invite for all attendees 3. Check if the outgoing mail was signed Actual Results: Kontact doesn't ask for the pass-phrase to sign/encrypt the invite mail. Therefore the mail isn't signed/encrypted Expected Results: Kontact should ask for the pass-phrase and sign/encrypt the invite according to the general settings in KMail. A checkbox for sign/encrypt in the attendees tab might be a good solution to implement this as an additional feature. Generally KOrganizer should refer to the outgoing mail standards in KMail. Therefore I file this for the Wishlist and not as a Normal bug.