Retrieval failed using IMAP4 protocol for message

Dglen00 is correct, although I think the syntax is

Set-MailboxCalendarSettings -Identity "Username" -AutomateProcessing None

The explanation is that Exchange 2007 has a Calendar Attendant that processes meeting requests on the server and adds them to your Outlook/Exchange Calendar automatically, whereas in Exchange 2003 this used to be handled by the Outlook Client. For a Mac Mail client using iCal, you don't want Exchange to process the meeting request, you want to let Mail retrieve the meeting request and pass it to iCal on the Mac. This command turns off the Calendar Attendant processing for this user.

References:
http://technet.microsoft.com/en-us/library/aa996340.aspx
http://technet.microsoft.com/en-us/library/aa998820(EXCHG.80).aspx

You can stop automatic Calendar processing on Exchange 2007 form the command shell.

Set-MailboxCalendarSettings "Username" -AutomateProcessing None

This resolves the problem IMAP clients.

You get this message, because you try to retrieve a message - obviously a calendar event- from an exchange server 2007, which does not store it in the Calendar folder anymore; that was the case in exchange 2003. Exchange 2003 creates MimeMessages with icalendar in Calendar folder. This is pretty standards conform. I noticed this during the development of a java client which retrieves the Calendar events from an exchange server over IMAP4.

I am afraid, only microsoft can help you by supporting it again or Apple should port MAPI to OS X or Mail should use Exhange 2007 Web Service interface. I have been searching for a java implementation of MAPI for a long time but I have already loosen the hope.


Exchange server uses two databases:
1. database is used for retrieving content - such as email from outside - and store it in the standards format.
2. one is used for MAPI clients such as Outlook. Whenever a MAPI client requests a content from the exchange server, it retrieves it from the first database, converts the content into own format saves it in this 2. database. This occures only one time. The next MAPI client requests on this content gets this already converted one.

I suggest, exchange server serves the IMAP4 requests from the 1. database. If you create an event with a MAPI client such as Outlook against an exchange 2007, the content will not be saved in the 1. database.

I would be interested in a solution too.

I need to add my 2 cents. I used to have no problems connecting from my Leopard MacBook to MS Exchange 2007 and getting calendar events. Now, all calendar events come back with this error. I don't think my sysadmin changed anything on our MS Exchange 2007 server. These arrived with a recent Leopard software update.

I have a user that is having this issue as well and it didn't start until a few days ago. He was using Mac Mail with Exchange 2007 quit fine for a few weeks. Are there any indications about what this fix really is?

Aside from just saying it's MS Exchanges fault when that has clearly not been the case for this user for several weeks?

Thanks!

Thanks for the answer, I'm having the same problem...
I tried typing the command in terminal but it says it isn't recognized... I'm supposing this is the command you'd have to type if you access to the Exchange Server?

Is there anything I can do to solve this problem on my end?
I'm getting email from a university, so I can't change server settings...

Thanks!

I'm having the same problem. Ever since I installed Office 2008, my meeting requests from PC's don't show up as attachments in Mail.app anymore.

Can you not type this command in from Terminal.app? I'm getting the same response from Terminal "command isn't recognized"