I have been toying with running secure pop and smtp email of late for a few roaming users as well as myself. It has been quite simple to setup running on Postfix and largely moves toward securing the transaction of checking email (other than from a man in the middle attacks, somewhat unlikely).
最近，我一直在为一些漫游用户以及我自己运行安全的pop和smtp电子邮件。 在Postfix上运行的安装非常简单，并且在很大程度上确保了检查电子邮件的事务(除了来自中间人的攻击，这种可能性不大)。
The beauty is leveraging Stunnel – which allows one to configure your preferred mail server as you wish and simply intercept your secure ports (for example Port 995 for POP3s and 465 for SMTP). This may not be the way to tacke it for the large scale as one can build secure configurations into the mail server – though it has worked nicely on a small scale for me during testing.
优点是利用Stunnel –允许您根据需要配置首选的邮件服务器，并仅拦截安全端口(例如POP3的Port 995和SMTP的465)。 尽管可以在邮件服务器中建立安全的配置，但这可能不是大规模解决此问题的方法-尽管在测试过程中它对我来说规模很小。
A bonus to use of Stunnel is its indifference to what mail server one is running – and its sole dependence fortunately is on OpenSSL – which most of us have by default on our boxes.
使用Stunnel的好处是，它对正在运行的邮件服务器无动于衷-幸运的是，它唯一依赖于OpenSSL-我们大多数人默认都将其安装在OpenSSL上。
Stunnel has a straightforward Man doc and some simple examples that will enable you to test quickly. Obviously insure your mail client handles SSL connections – fairly universal at this point.
Stunnel有一个简单的Man文档和一些简单的示例，这些使您可以快速进行测试。 显然，请确保您的邮件客户端可以处理SSL连接-此时相当普遍。
I also had a bit of a dated HowTo in my links that serves up a more in-depth example. This article also addresses opening up iptables firewall ports, configuring xinetd and includes IMAP information.
我的链接中也有一些过时的HowTo，它提供了更深入的示例 。 本文还介绍了打开iptables防火墙端口，配置xinetd并包括IMAP信息。
翻译自: https://www.sitepoint.com/use-stunnel-to-secure-pop-imap-and-smtp/
相关资源：jdk-8u281-windows-x64.exe