SPEmailAttachmentCollection attachColl = emailMessage.Attachments;
    string AttachedFiles = string.Empty;
    int TotalAttachments = 0;
    foreach (SPEmailAttachment attach in attachColl)
    {
        AttachedFiles += attach.FileName + ";";
        TotalAttachments ++;
    }

SPItem item = file.Item;
    item["TotalAttachments"] = TotalAttachments.ToString();
    item["AttachedFiles"] = AttachedFiles.ToString();
    item.Update();
    list.Update();