webApi MailKit 发送邮件附件，中文附件名在QQ邮箱乱码

Question

public static IList<MimePart> GetMimePartList() { IList<MimePart> mimePartList = new List<MimePart>();var current = HttpContext.Current;if (current != null) { HttpRequest request = current.Request; HttpFileCollection files = request.Files;int filesCount = files.Count;for (int i = 0; i < filesCount; i++) { HttpPostedFile item = files[i]; MimePart attachment = new MimePart(item.ContentType) { ContentObject = new ContentObject(item.InputStream, ContentEncoding.Default), ContentDisposition = new ContentDisposition(ContentDisposition.Attachment), ContentTransferEncoding = ContentEncoding.Base64, FileName = item.FileName }; mimePartList.Add(attachment); } }return mimePartList; }