Error when accessing MIME-Content of emails through EWS

Question

Hello,
i've a problem downloading the mime-content of some emails using exchange web services. Here is the code i'm using:
            exService = new ExchangeService();
            exService.Credentials = new NetworkCredential("user", "password", "domain");
            exService.Url = new Uri(@"https://server/ews/Exchange.asmx");
            fFolder = this.GetPublicFolder(exService, null, "Test");
            ivItem = new ItemView(int.MaxValue);
            ivItem.PropertySet = new PropertySet(BasePropertySet.FirstClassProperties, pdbProperties);
            ivItem.OrderBy.Add(ItemSchema.DateTimeReceived, SortDirection.Ascending);
            fiResults = fFolder.FindItems(ivItem);
            foreach (Item iItem in fiResults.Items)
                    psItem = new PropertySet(BasePropertySet.FirstClassProperties, ItemSchema.MimeContent);
                    iItem.Load(psItem);
Calling the Load-method throws an Microsoft.Exchange.WebServices.Data.ServiceResponseException (Errorcode "Microsoft.Exchange.WebServices.Data.ServiceError.ErrorMimeContentConversionFailed") with errortext "Fehler beim Konvertieren des MIME-Inhalts." ("Error
converting the MIME-content" in english). Both emails have an appointment-attachment, one of them a ICS-file, which is named as "not supported calendar message". I've tried to delete the attachments and access the emails again, but the exception still occures.
With thousands of other mails, the code runs without problems.
I also analysed the messages with Outlook Spy, but i found nothing special, except that the one with the ics-file contains the message class "IPM.Note.NotSupportedICal" (the other is "IPM.Note").
My question is, what can be the reason for this exception, especially for the e-mail without the unsupported attachment? And what can i possibly do to avoid it/to get the mime-content anyway? I'm using the code to export the e-mails as EML-files.
Thank you in advance for your answers.
Regards
DanielLW

Answer 1

Not sure about the EWS Managed API but with the web services, if you remove the request for the body of the item (<t:FieldURI FieldURI="item:MimeContent"/>) it seems to resolve the issue, since it no longer needs to convert between the
'IPM.Note.NotSupportedICal' (non-Exchange calendar entry?) and 'IPM.Note' classes (a normal email).