Dev tools · alternatives · 2026
24 alternatives to RustMailer
A self-hosted IMAP/SMTP middleware designed for developers
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
- 1
I am happy to announce Stalwart JMAP [1], an open-source JSON Meta Application Protocol server that aims to be scalable, robust and secure. Some of its key features are: - JMAP Core, JMAP Mail and JMAP over WebSocket full compliance. - IMAP4 rev2/1 support via Stalwart IMAP, an imap-to-jmap proxy [2]. - Scalable and fault tolerant: consensus over Raft, node autodiscovery over gossip and read-only replicas. - RocksDB backend with full-text search support in 17 languages. - OAuth 2.0 authorization code and device authorization flows. - Domain Keys Identified Mail (DKIM) message signing. -…
2022 · github.com · its alternatives →
- 2OS
I've been working on this for some time now, starting with vm2, then deno-core for 2 years, and recently rewrote it on rusty_v8 with Claude's help. OpenWorkers lets you run untrusted JS in V8 isolates on your own infrastructure. Same DX as Cloudflare Workers, no vendor lock-in. What works today: fetch, KV, Postgres bindings, S3/R2, cron scheduling, crypto.subtle. Self-hosting is a single docker-compose file + Postgres. Would love feedback on the architecture and what feature you'd want next.
Jan 2026 · openworkers.com · its alternatives →
- 3IA
2020 · imapapi.com · its alternatives →
- 4
Sidemail 2.0▲306Hi all! I'm Kristyna, maker of Sidemail. I'd love to share with you what we've been building. We built Sidemail because sending emails from a SaaS app was way harder than it should be. Sidemail is made for developers and teams that want one simple place to handle SaaS emails with reliable delivery and no bloat. It has: - Everything for creating, managing and delivering SaaS emails in one platform, - Easy-to-use email API for sending password resets, receipts, etc. - Messenger for writing product updates and newsletters, - Email automations for onboarding and lifecycle flows, - Fast email…
Nov 2025 · sidemail.io · its alternatives →
- 5
EmailEngine▲165Access any email account to receive/send emails with an API
2021 · emailengine.app · its alternatives →
- 6
I am happy to announce Stalwart SMTP [1], a modern SMTP server developed in Rust with a focus on security, speed, and extensive configurability. It features built-in DMARC, DKIM, SPF and ARC support for message authentication, strong transport security through DANE, MTA-STS and SMTP TLS reporting, and offers great flexibility and customization thanks to its dynamic configuration rules and native support for Sieve scripts. The project has been recently awarded a grant from NLNet and the European Commission's Next Generation Internet program to develop a mail server in Rust. The next step in…
2023 · github.com · its alternatives →
- 7
Everything you need to start sending newsletters, drip campaigns, transactional emails. Mailcoach is a fully featured email marketing platform built for growing creators, developers, and businesses.
2020 · mailcoach.app · its alternatives →
- 8
High performance, self-hosted, newsletter and mailing list manager with a modern dashboard. Single binary app. - knadh/listmonk
2019 · github.com · its alternatives →
- 9
- 10
- 11WS
WildDuck is a scalable no-SPOF IMAP/POP3 mail server
2019 · wildduck.email · its alternatives →
- 12
A fast, self-hosted MailHog alternative built in Rust
Mar 2026 · rustmail.app · its alternatives →
- 13
Mailcheap▲123Email hosting, dedicated email servers, API-first platform
2018 · mailcheap.co · its alternatives →
- 14
Microservice based mail client built with ReactJS and Spring
2019 · github.com · its alternatives →
- 15
Introducing Posthorn, a self hosted email gateway. One docker container (or Go binary) between every self hosted app on your VPS and your transactional email provider. Set up Posthorn once, point your apps to it, done. I was trying to deploy Ghost on a DigitalOcean droplet and found that DO and many different VPS services have started to block the default SMTP ports to try to combat the various types of abuse they get. To actually configure my app, I had to hack together a Postfix relay. In another project, I had a static site which had a contact form, but my free Formspree account was…
May 2026 · github.com · its alternatives →
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- 18
Groupmail▲80Self-hosted newsletter app for Mac, Windows & Linux
2020 · groupmail.io · its alternatives →
- 19
Listmonk 1.0▲110Self-hosted newsletter and mailing list manager
2021 · github.com · its alternatives →
- 20
- 21
- 22
- 23
Find quality emails from a domain and verify their validity
2022 · minelead.io · its alternatives →
- 24VM
2016 · varmail.me · its alternatives →
Also compare
- Distributed JMAP and IMAP Servers in Rust alternatives
- OpenWorkers – Self-hosted Cloudflare workers in Rust alternatives
- IMAP API – Self-hosted access to IMAP over REST alternatives
- Sidemail 2.0 alternatives
- EmailEngine alternatives
- SMTP Server in Rust with DMARC, Dane, MTA-STS, Sieve, OTEL Support alternatives
Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →