Open-source ImprovMX alternatives

SimpleLogin is an email alias service that protects your online identity. The idea is that your email address works as an identity, and using the same one everywhere makes it easy to track you, so you create a separate alias for each site and forward mail to your real inbox.

This repository contains the back end and web app, and its README is mainly a guide to self-hosting. You need a Linux server, with at least 2 GB of RAM recommended because most components run as Docker containers, open ports for email, web and SSH, and a domain whose DNS you can configure. Once your instance is running, you can point the SimpleLogin Chrome and Firefox extensions and the Android and iOS apps at your own server by changing the API URL.

SimpleLogin is written in Python with Flask and licensed under AGPL-3.0. The roadmap and forum are kept on GitHub, where users can submit ideas and vote on features. The vendor also operates a hosted service at simplelogin.io.

addy.io, formerly AnonAddy, is an anonymous email forwarding service. You create aliases that forward to your real mailbox, which lets you give out different addresses without exposing your own. This repository is the source code for self-hosting addy.io, which is written in PHP and licensed under AGPL-3.0.

The project's FAQ lists shared domain aliases and standard aliases, the ability to use your own domain, replying to or sending from an alias so your real address stays hidden, and adding your own GPG or OpenPGP key to encrypt forwarded messages. It also covers attachments, spoof-warning banners, deleting an account and which mail providers are compatible. A browser extension, Android and iOS apps and a Raycast extension are mentioned.

The FAQ refers to Free accounts, which indicates a free tier on the hosted service, and it discusses where the server is located and what to do if you do not trust the operator, for which self-hosting is the answer. The project positions itself for people who want to limit spam and protect their identity when signing up to websites.

Forward Email is an open-source email service focused on privacy. It handles custom-domain email forwarding and also provides mailboxes accessible over IMAP, POP and SMTP, with encryption using algorithms such as AES-256 and ChaCha20, and it positions itself as an all-in-one alternative to Gmail, Mailchimp and Sendgrid.

Its topics and documentation point to features such as sending mail, newsletters, SQLite-based storage, push notifications, and calendar and contact support through CalDAV and CardDAV, plus autodiscovery records and Domain Connect integration for setting up DNS. The README includes a local development guide and detailed notes on server infrastructure, load balancing, provisioning and deployment, including automated setup with Ansible.

The code is JavaScript and the project says it is fully open source, so the service can be inspected and, with the published infrastructure guidance, run on your own servers. Most consumers simply use the hosted service at forwardemail.net. It suits individuals and small organizations that want private email on their own domain and developers interested in how such a stack is built.