Hi List, after solving the first problem now we have another question. We see every ~2 hours something like this: 2013-03-26 12:26:39+0100 [-] [mailgateway] 2013-03-26 12:26:39+0100 [IMAP4DownloadProtocol,client] [twistedcaldav.mail.MailHandler#warn] Mail gateway didn't find an ORGANIZER in REPLY <some_very_long_string_of_numbers_and_letters@mailserver_example.com> Does this mean the organizer is not know to our our server, or the organizer is not know to the remote server? Or does this mean there is no organizer in the *.ics file? Another thing we see more often is: 2013-03-26 11:49:30+0100 [-] [caldav-2] [PooledMemCacheProtocol,client] [twistedcaldav.scheduling.scheduler.ScheduleResponseQueue#error] Error during POST for mailto:user@example.com: iMIP request failed 2013-03-26 11:49:33+0100 [-] [caldav-0] [PooledMemCacheProtocol,client] [twistedcaldav.scheduling.imip#error] Could not do server-to-imip request : <twistedcaldav.scheduling.imip.ScheduleViaIMip object at 0x10b3e0550> iMIP VFREEBUSY REQUESTs not supported. What's here the problem? We're still onMac OSX Lion 10.7.3 and we want to fix these problems so ervey useful hint or link is appreciated. Thanks, Sirko ------------------------------------------------------------------------------------------------ Datameer GmbH, Grosse Ulrichstrasse 7-9, D-06108 Halle (Saale), Amtsgericht Stendal, HRB: 10348, Geschäftsführer: Stefan Groschupf