A Mastodon to email client Gateway

MOP3 is a toy-ish, standards complient-ish server that speaks POP3/SMTP which serves data from your home Mastodon timeline. This enables email clients from as early as the 1980s and as recent as today to receive, send, and reply to Mastodon posts (including images). This was started as a retro-computing project, however I’ve used it as my main client during development, as even modern email clients like Apple’s Mail.app and Windows Mail support POP3 and SMTP. MOP3 can be configured to encode posts in Unicode or ASCII, with or without HTML, and images either as links, or attachments.

Installation

Binaries are available for Windows, Mac, and Linux on the releases page. This is written in Rust, so running cargo install mop3 on your host should install it. If not, downloading the repo and running cargo build should also work.

Usage

This requires an access token, which can be obtained in Preferences -> Development -> New Application on your Mastodon account. The client key and secret are not required.

mop3 --help will give you all of the important runtime flags. None are required, but --token is reccomended to avoid sending your access token over TCP, and required for posting since SMTP authentication is not implemented. I reccomend the --ascii flag for retro clients, and --html --inline for modern clients.

To connect to it, point your client at the server ip/port, set the username to “username@instance.com“, the password to your account token, and disable SSL/TLS/SPA/SMTP authentication. If --token is used, the password can be anything. Some clients