Hi, I have a current snapshot of DCS 3.0 running on my Linux server. iCal 4 works great as a client. I can create events and then DCS sends a mail to external participants. Now I wanted to use Lightning on another computer with that account. I am using 1.0b3pre. Accessing events and todos works great. But I expected the server to handle the invitations now. Creating an event an invitation is send by Thunderbird and not by the server. How does DCS determine when to send mails and when not? Has anybody Lightning integrated? regards Felix btw. Does iCal have the possibility to send client side invitations? Using Lightning i can influence this by DAV: 1, 2, 3, access-control, calendar-access, calendar-schedule removing calendar-auto-schedule to the HTTP header.