public async Task Attachment(MailWindow inboxPage, User user, ConfigModel conf, string Atch, string destination)
{
using (ImapClient client = new ImapClient())
{
await client.ConnectAsync(conf.ImapServer, conf.ImapPort);
client.Authenticate(user.Mail, user.Password);
IMailFolder Folder = client.GetFolder(ListMessages.fold);
await Folder.OpenAsync(FolderAccess.ReadWrite);
IList <IMessageSummary> atc = Folder.Fetch(new[] { LastOpenId }, MessageSummaryItems.Body);
var multipart = (BodyPartMultipart)atc.First().Body;
var attachment = multipart.BodyParts.OfType <BodyPartBasic>().FirstOrDefault(x => x.FileName == Atch);
TransferProgress progress = new TransferProgress();
Downloads FileDownload = new Downloads();
FileDownload.Show();
var file = Folder.GetBodyPart(LastOpenId, attachment, default, progress);