We describe a simple approach to peer-to-peer electronic mail that would allow users of ordinary workstations and mobile devices to exchange messages without relying upon third-party mail server operators. Crucially, the system allows participants to establish and use multiple unlinked identities for communication with each other. The architecture leverages ordinary SMTP for message delivery and Tor for peer-to-peer communication. The design offers a robust, unintrusive method to use self-certifying Tor onion service names to bootstrap a web of trust based on public keys for end-to-end authentication and encryption, which in turn can be used to facilitate message delivery when the sender and recipient are not online simultaneously. We show how the system can interoperate with existing email systems and paradigms, allowing users to hold messages that others can retrieve via IMAP or to operate as a relay between system participants and external email users. Finally, we show how it is possible to use a broadcast protocol to implement mailing lists and how distributed ledger technology might be used to bootstrap consensus about shared knowledge among list members.

中文翻译：

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无服务器电子邮件

我们描述了一种简单的点对点电子邮件方法，它允许普通工作站和移动设备的用户在不依赖第三方邮件服务器运营商的情况下交换消息。至关重要的是，该系统允许参与者建立和使用多个未关联的身份进行相互通信。该架构利用普通 SMTP 进行消息传递，利用 Tor 进行点对点通信。该设计提供了一种强大的、非侵入式的方法来使用自我认证的 Tor 洋葱服务名称来引导基于公钥的信任网络，以进行端到端的身份验证和加密，反过来，当发件人和收件人不同时在线。我们展示了系统如何与现有的电子邮件系统和范式进行互操作，允许用户保存其他人可以通过 IMAP 检索的消息或作为系统参与者和外部电子邮件用户之间的中继运行。最后，我们展示了如何使用广播协议来实现邮件列表，以及如何使用分布式账本技术来引导列表成员之间共享知识的共识。