在MailKit中显示抓取进度

var progress = new Progress<TransferProgressEventArgs>();
progress.ProgressChanged += (sender, args) =>
{
    // 在这里处理进度变化事件
    Console.WriteLine($"已接收 {args.BytesTransferred}/{args.TotalBytes} 字节");
};

using (var client = new ImapClient())
{
    client.Connect("imap.example.com", 993, true);
    client.Authenticate("username", "password");

    var inbox = client.Inbox;
    inbox.Open(FolderAccess.ReadOnly);

    // 抓取邮件，并传递进度监视器对象
    inbox.Fetch(0, -1, MessageSummaryItems.Full, progress);
}