Email

Listmonk22.7k★

Listmonk is a self-hosted newsletter and mailing list manager, the open source answer to Mailchimp. It's a single Go binary backed by Postgres that handles subscriber management, campaign creation, analytics, and sending, all through a clean web UI. Connect it to any SMTP service (Amazon SES, Postmark, your own server) and you're running your own Mailchimp for the cost of a VPS. What makes Listmonk stand out: performance. It can handle hundreds of thousands of subscribers without breaking a sweat. The templating system is flexible, transactional emails work alongside campaigns, and the API is well-documented for programmatic access. Subscriber segmentation, A/B testing, bounce handling, it's all there. Deployment is dead simple compared to alternatives. Docker Compose up, point it at a Postgres database, configure SMTP, done. The whole thing runs on a $10/mo VPS comfortably for 50K+ subscribers. The catch: no drag-and-drop email builder. You write HTML templates or use the built-in markdown editor. If your marketing team expects a visual builder like Mailchimp's, they'll be disappointed. There's no built-in landing page builder or signup form designer either; you build those yourself or use the embed code. And the community, while growing, is smaller than commercial ESPs; you're on your own for advanced deliverability tuning.

Nodemailer17.6k★

Nodemailer is the standard library for sending emails from Node.js. It's been the standard for sending email in Node.js for over a decade. Completely free under a permissive license. You get SMTP support, OAuth2 authentication, HTML and plain text emails, attachments, embedded images, DKIM signing, and connection pooling. It works with any SMTP server: Gmail, SendGrid, Mailgun, Amazon SES, your own Postfix server, whatever. No paid tier, no hosted service. It's a library. You install it, configure your SMTP credentials, and send emails. Everyone building Node.js apps that send email: use Nodemailer as your transport layer. Pair it with an ESP (email service provider) for deliverability. If you're sending marketing emails or newsletters, use a dedicated platform instead. The catch: Nodemailer sends emails. That's it. It doesn't manage email templates, track opens/clicks, handle unsubscribes, or give you analytics. For those, you need a service like Resend, SendGrid, or Mailgun on top. Also, sending emails reliably at scale (deliverability, reputation management, bounce handling) is a whole discipline that Nodemailer doesn't solve. It just sends.

Postal16.7k★

Postal is a self-hosted mail delivery platform for transactional email: password resets, order confirmations, notifications, all on infrastructure you own instead of paying per email through SendGrid. You run your own email server, control your sending reputation, and pay nothing per message. MIT license, Ruby. Full-featured: SMTP server, HTTP API, webhook delivery tracking, click/open tracking, bounce handling, multiple organizations and mail servers, IP pool management. Web UI included for monitoring and configuration. Fully free to self-host. No paid tier. Your costs are infrastructure: a VPS ($10-20/mo), a dedicated IP with clean reputation, and the time to set up DNS records (SPF, DKIM, DMARC). Solo developers sending a few hundred emails/month: overkill. Use Resend's free tier. Small teams sending thousands/month: Postal starts making financial sense when you'd otherwise spend $50-100/mo on an ESP. Medium to large orgs sending 100K+/month: Postal pays for itself quickly: at $0.001/email on SendGrid, 100K emails is $100/mo. Postal costs you a $20 VPS. The catch: email deliverability is hard. Running your own mail server means YOU are responsible for IP reputation, authentication records, warming up IPs, handling bounces correctly, and staying off blacklists. Get any of it wrong and your emails land in spam. This is not a 'set and forget' system. Budget 4-8 hours/month of ops minimum.

Mailtrain5.7k★

Mailtrain is a self-hosted newsletter platform that handles subscriber management, campaign creation, automation, and analytics without per-subscriber fees. You install it on your own server, connect it to an SMTP service (Amazon SES, Postmark, your own mail server), and manage subscribers, campaigns, and automations from a web UI. It handles list management, segmentation, A/B testing, templates, and basic automation triggers. The UI is functional, not beautiful, but it gets the job done. Import/export subscribers via CSV, track opens and clicks, manage bounces. Version 2 added a drag-and-drop template editor and better automation workflows. It uses MySQL/MariaDB for storage and can handle large lists (100K+ subscribers) with proper infrastructure. The catch: development has slowed significantly; commits are sporadic and the community is small. The setup isn't trivial: you need Node.js, MySQL, Redis, and an SMTP relay, plus DNS records for DKIM/SPF. If something breaks, you're debugging it yourself. And the UI feels dated compared to modern alternatives. Listmonk has largely overtaken Mailtrain as the go-to self-hosted newsletter tool. It's faster, simpler to deploy (single binary + Postgres), and more actively maintained.

james-project1.0k★

Apache James is a mail server you can program. SMTP, IMAP, POP3, and JMAP work out of the box, but the point is the mailet framework: drop your own Java classes into the processing pipeline and route, filter, or transform every message with custom logic. All of it is free under Apache 2.0, from a foundation project that has been at this for two decades. Running it is a real commitment. The simple setup (one JVM with local storage) is manageable, but the distributed flavor wants Cassandra, OpenSearch, S3-compatible storage, and RabbitMQ before it says hello. Then add the usual self-hosted email tax: reverse DNS, SPF, DKIM, DMARC, and IP reputation are all your problem. This is infrastructure work, not a weekend Docker project. Use James when email is part of the product: you're building mail handling into a platform, or you need processing rules a normal mail server can't express. Teams that just want mailboxes should pay Google Workspace or Fastmail and move on. For self-hosted sending without the Java, Postal is the better fit. The catch: James is a toolkit wearing a server costume. The docs assume Java fluency, the community is small next to mainstream mail stacks, and every custom mailet you write is code you maintain forever.