标题和邮件正文为中文时都是乱码

[tqangxl]

标题和邮件正文为中文时都是乱码
Subject =?us-ascii?Q?Oracle=3F=3F=3F=3F=3F=3F=3F=3F=3F=3F?=

UTF-8? gbk？

附件能不能在下载的旁边加个查看的选项，不用下载直接浏览器查看所点击的附件

[axllent]

I am sorry but I don't speak or understand Chinese. Based on Google translate however you have two questions:

1. Is your email & subject properly encoded (UTF8 / base64)? =?us-ascii?Q?Oracle=3F=3F=3F=3F=3F=3F=3F=3F=3F=3F?= is the same as Oracle??????????? so I do not understand what you expect. Does this work in any other email client correctly? It is my understanding that you will need to use UTF-8. Maybe you could take a look at https://dencode.com/string/quoted-printable to test.
2. Your browser can only open the file formats it supports - if the browser does not support the format (eg: .man) then it will try download the file instead. Mailpit does not convert attachment formats into something your browser can understand (there are literally thousands of file formats).