Hi all I'm getting desperate with ICalendar and Exchange, hopefully someone here can help me out. Current situation: I have an application which sends ICalendar invitations over SMTP. Invitations can be opened in Outlook and they show up correctly with Accept/Decline/Tentative options. Invitations can be opened with Outlook and Thunderbird Lightning, so ICalendar format should be just fine. UNLESS message is sent to recipient who is using MS Exchange. With Exchange message just disappears without even delivery failure reply. Email message has inline ICalendar content, with Content-Type: text/calendar; method=REQUEST; encoding="utf-8" Tests done so far: Receiving Exchange will accept invitations which are send using Outlook or Lightning through 3rd party email server. - Outlook 2000 invitations has inline ICalendar just as in my application - Lightining is sending invitation in attachment I have been sending invitations from Outlook and from our system to separate email account and comparing the message contents / headers without any luck. They look identical to me, but our invitations are not going through while Outlook one works. Software used: Mail Server: MailEnable - Invitations sent using Thunderbird through this server works, so it's not mail server issue, I think Mail Component: ChilkatSoft .NET Email - Invitations go through to any client unless message enters Exchange (my primary suspect right now) Currently it seems that ICalendar content is not the problem as I haven't been able to get even one invitation to go through, even with using the most simple 'PUBLISH' sample from Wikipedia. Any ideas how to start solving this problem. I have not access to Exchange logs. Cheers
