I'm replying with my BlackBerry so I'll need to be brief :) Outlook cannot handle smime protected calendar emails. The upcoming version of Djigzo allows you to disable signing and or encryption of calendar items. I hope to release the new version in the beginning of January. If you want to test the upcoming release you need to wait till I getback (I don't have the URLs here) or perhaps Andreas can post the URLs here. Kind regards, Martijn -----Original message----- As far as i know this is only available in the not-yet-released Djigzo 1.3 and later. From a "private" post regarding upcoming 1.3 version: --- Djigzo open source email encryption