public static void ThrowIfMeetingResponseInvalid(MeetingMessage meetingMessage) { MeetingUtilities.ThrowIfWebParts(); MeetingRequest meetingRequest = meetingMessage as MeetingRequest; if (meetingRequest != null && meetingRequest.IsMailboxOwnerTheSender()) { throw new OwaOperationNotSupportedException(LocalizedStrings.GetNonEncoded(679811893)); } MeetingUtilities.ThrowIfInArchiveMailbox(meetingMessage); }