using (MercatorOutlook.OutlookApplication outlookApplication = new MercatorOutlook.OutlookApplication(MercatorUi.Globals.Langue))
{
    if (outlookApplication == null)
        return;
    using (MercatorOutlook.NameSpace outlookNameSpace = outlookApplication.NameSpace)
    {
        if (outlookNameSpace == null)
            return;
        MercatorOutlook.DefaultFoldersEnum typeFolder = MercatorOutlook.DefaultFoldersEnum.FolderCalendar;
        using (MercatorOutlook.Folder itemsFolder = outlookNameSpace.GetDefaultFolder(typeFolder))
        {
            if (itemsFolder != null)
            {
                using (MercatorOutlook.Item item = itemsFolder.Add())
                {
                    item.Subject = "Test";
                    item.Location = "Mecalys";
                    item.Body = "Corps du message";
                    item.Start = DateTime.Now.AddHours(2);
                    item.End = DateTime.Now.AddHours(4);
                    item.MeetingStatus = MercatorOutlook.OlMeetingStatus.olMeeting;
                    MercatorOutlook.Recipient sentInvite1 = item.RecipientsAdd("Jean Dupont <jd@test.com>");
                    sentInvite1.Type = MercatorOutlook.OlMeetingRecipientType.olRequired;
                    MercatorOutlook.Recipient sentInvite2 = item.RecipientsAdd("Arnold Deluxe <ad@test.com>");
                    sentInvite2.Type = MercatorOutlook.OlMeetingRecipientType.olOptional;
                    item.RecipientsResolveAll();
                    item.Send();
                    item.Save();
                }
            }
        }
    }
}