Calendar E-Mail Extension – Status replies cannot be processed

Applies to the Calendar E-Mail Extension.

With the Calendar E-Mail Extension you can organize meetings in a SharePoint Calendar and invite attendees directly from SharePoint using e-mail meeting requests. The attendees can then accept or decline the invite. This status reply should be processed by the SharePoint Calendar and the status reply and the detailed communication should be visible in the calendar event.

First let me explain how the communication works:

The enhanced SharePoint calendar sends a meeting request to all attendees and uses the e-mail alias configured in the list’s communication settings as the sender and as the reply to address.

If an attendee accepts, declines or sends any other response, the reply email will be routed to the mail drop folder on the SharePoint application server. Usually c:\inetpub\mailroot\Drop.

Incoming e-mails are processed periodically, usually every 5 minutes depending on the timer settings of the “Immediate alerts” job.

If the eml-file disappears from the drop folder, the status should be updated in the event’s “Invite Status” field.

If this is not the case, there are a few things you can check.

1. Make sure the eml-file appears in the drop folder

If this is not the case, make sure incoming emails are configured correctly.


  • Incoming E-Mails in Central Administration,
  • SMTP Service on the SharePoint server and
  • the Send Connector in Exchange or any other mail server.

2. If the eml-file appears in the drop folder, open it with a text editor and look for text/calendar.

If there is no text/calendar part, but you find a winmail.dat attachment you have to disable TNEF on Exchange. Transport Neutral Encapsulation Format (TNEF), also known as Outlook Rich Text Format, is a Microsoft-specific format for encapsulating MAPI message properties. SharePoint will not understand this encapsulation format, so tell your Exchange admin to disable TNEF for this domain on exchange.
This post shows how to configure it:


If the eml-file looks fine and the status is still not updated when the eml disappears from the drop folder, send an e-mail to and we will support you troubleshooting the issue.