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Notes from building a self-hosted email platform
Technical deep-dives, design decisions, and lessons from the Broadcast team, written for developers who care about how things actually work.
Broadcast Fits on a 2 GB Server Again
Each new background worker in Broadcast is a full copy of the application, and a 2 GB server started to swap during large sends. Broadcast 2.44 adds Low memory mode: the whole job server runs in one process, chosen on the Jobs page, with no SSH needed.
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Login Codes No Longer Wait Behind Your Newsletter
How Broadcast now decides which email goes first, keeps part of each server’s hourly limit for login codes, and makes large broadcasts wait without going over the limit.
I Priced Out Vibe-Coding a Copy of My $250 App
I used Broadcast’s full git history to estimate what it costs to rebuild it with Claude Opus 5.5, on the API and on a Claude Max plan. The numbers, the method, and when building your own is the right call.
Let Subscribers Choose Which Emails They Get, Instead of Losing Them Entirely
Broadcast 2.41 adds subscriber topics, per-topic unsubscribe, a hosted preference page and a consent webhook for every choice.
Your Team Should Not Need English to Send Your Newsletter
Broadcast 2.39 lets every user run the email marketing dashboard in one of twelve languages, chosen per person, without changing what subscribers see.
When a Send Breaks Halfway, Pick Up Where It Stopped
Broadcast 2.38 resumes failed broadcasts without double-sending, holds webhook events through an outage, and shows the source of every suppression.
How to Build a Salesforce Email Template With a Free Drag-and-Drop Builder
Design a responsive HTML email in a free drag-and-drop builder, then paste it into Salesforce Lightning Email Templates or Account Engagement (Pardot). Menu paths, merge field syntax, and the limits to watch for.
One Webhook When You Purge a List, Not Thousands
Broadcast sends a single subscribers.purged webhook when you purge a channel’s subscribers, and subscribers.purge_failed if the purge stops partway, so connected tools can keep up.
Was passiert, wenn das Data Privacy Framework fällt?
Das EU-US Data Privacy Framework steht unter Druck. Was ein Wegfall für Newsletter-Tools aus den USA bedeuten würde, plus eine Checkliste für den DSB.
Let Claude Code Run Your Email Marketing, and Script Your Team
Broadcast 2.35 adds a built-in MCP server at /api/mcp for Claude Code and other clients, a Users API for provisioning users and permissions, per-token API rate limits, and a Last Emails tab that shows every email a subscriber received.
A Drag-and-Drop Email Builder That Starts From Your Brand
Broadcast 2.34 adds a drag-and-drop email builder for broadcasts, templates and sequences, with a channel brand kit, a preview as any subscriber, and emails rendered as table-based HTML that works in Outlook.
Two-Factor Authentication, and Letting Cloudflare Do It for You
Broadcast 2.32 adds two-factor authentication with recovery codes, installation-wide enforcement with a grace period, and automatic sign-in for users who pass Cloudflare Access.
Working in Two Channels at Once, Without Them Getting Mixed Up
Broadcast now puts the channel in each page’s address, so two browser tabs can work in two different channels without interfering with each other.
DigitalOcean blocks ports 25, 465, and 587. Here is what to do.
DigitalOcean blocks outbound SMTP on ports 25, 465, and 587. Confirm the block from your droplet in one command, get email sending again on port 2525 today, and appeal the block.
This and this, but not that
Why Broadcast’s segment builder hid its AND condition in plain sight, what 2.30 changes about it, and the data-loss bug that turned up while fixing it.
The upgrade that never finished
Why a self-hosted upgrade can hang forever on a Postgres lock, what Broadcast 2.28 changes about it, and the Postmark stream and multi-server work that shipped alongside.
Verify every address you send from, not just the first one
Broadcast now verifies every sender identity on a channel with your email provider, deep-links the warnings to the address they name, and reconciles DNS Health with the provider’s own verdict.
Announce every release automatically, with an email you still get to approve
Broadcast autopilots can now watch your releases and draft a product update email for each new version, complete with your screenshots and docs links, ready for review.
Permissions You Can Read at a Glance, and Grant Twenty Channels at a Time
Broadcast 2.24 rebuilds channel permissions around readable roles, plain-language summaries, and bulk apply across many channels at once.
Knowing When Your Own Server Goes Down
Broadcast 2.25 adds opt-in server health monitoring with down and recovery emails, a diagnose command that collects a support bundle, and a fix command that repairs installation drift.
One Bounce Should Block an Address Everywhere
Copy a channel’s suppression list to the global list in one action, and manage both lists through the API: how suppressions work across multiple channels in Broadcast 2.23.
The Segment That Quietly Matched Nobody
Broadcast 2.21 adds a Maintenance section that finds imported data the app cannot use (starting with dates) and repairs it after showing you exactly what would change.
You Should Know What an Error Report Sends
Broadcast 2.20.1 fixes the Send Report button on the error page and shows you exactly what it will transmit, with email addresses, keys and tokens stripped out.
Your Install Should Tell You When It’s Out of Date
Broadcast 2.20 tells you when a newer version is available, lets you turn that check off, and lets you reopen the What’s New tour for any past release.
Export What You’re Looking At: CSV for Subscribers, Broadcasts and Activity
Broadcast 2.19 adds CSV export for subscribers, broadcast performance, and per-recipient activity, scoped to whatever your current search and filters are showing.
One Customer’s Feedback Email, Shipped
Broadcast 2.18 ships a round of customer-requested improvements: domain search, a sortable per-recipient activity table, template and segment cloning, template tags, and opens and clicks in subscriber activity.
A Backup on the Same Server Isn’t a Backup
Broadcast 2.17 adds automatic off-server backups to any S3-compatible object storage, with connection testing, upload status, retry, and remote retention.
The 200 That Didn’t Do What You Asked
Broadcast 2.16 adds API response warnings for successful-but-surprising requests, an Idempotency-Key header for transactional email, and confirmed_at on subscriber creation.
Ask AI: An Email Marketing Assistant You Actually Own
Ask AI is Broadcast’s in-app assistant. Bring your own API key, pick the model, and keep subscriber data on your server. Included in the license, no AI tier.
Your SPF Record Will Break When You Least Expect It
Broadcast monitors your SPF, DKIM, and DMARC records continuously and alerts you when a healthy record breaks. Built in, no separate monitoring subscription.
Email Marketing Software Your AI Agent Can Actually Drive
How Broadcast 2.0 exposes a first-class surface for AI agents like Claude Code to discover, configure, and operate a self-hosted email marketing platform.
Autopilot: The Newsletter That Writes Its First Draft Itself
Autopilot drafts your newsletter from GitHub commits, RSS feeds, and web pages, in your voice, with a review step before anything sends. Ships in the license.
Nobody Reads the Changelog
Broadcast 2.15 introduces a What’s New tour that walks you through the features added since your last version, with a screenshot and a link to try each one.
Making Broadcast Sends Bulletproof: Safe to Crash, Safe to Retry, Safe to Resume
How Broadcast v2.12 made bulk sending idempotent, retryable, and resumable with Postgres constraints and Active Job. A technical walkthrough.
Double Opt-In Without the Straitjacket
Double opt-in in Broadcast: API-first confirmation, editable templates, six customizable page states, and redirects to your own domain.
Your List, Your Data Model
How Broadcast treats subscribers as records you shape: custom data fields, opt-in form blocks, CSV column mapping, and typed segmentation with self-updating relative date rules.
An AI That Reads Your Actual DNS, Not a Blog Post About DNS
Broadcast 2.14 connects Ask AI to real SPF, DKIM and DMARC check results for your domains, so deliverability answers reflect your actual DNS rather than generic advice.
The True Cost of Email Marketing at Scale (2026)
A three-year cost comparison of email marketing as your list grows from 1k to 100k subscribers: Mailchimp, Beehiiv, and ConvertKit subscriptions vs. self-hosted Broadcast.
Why We Sell a One-Time License in a Subscription World
Why Broadcast is sold as a one-time license instead of a subscription: the incentive alignment, the trade-offs, and what owning your software actually means.
Importing a List Shouldn’t Require Rewriting the File First
Broadcast 2.11 adds a preview-and-map step to subscriber imports: see the first rows, map each column to email, name, tags or custom data, and choose your tag separator.
EU Data Sovereignty for Email Marketers in 2026: The Regulatory Floor Just Moved Again
A developer’s read on EU data sovereignty for email marketing in 2026: DPF, CLOUD Act, NIS2, and what self-hosting actually fixes.
Ask the Question at Signup, Not in a Survey Six Months Later
Broadcast 2.10 adds a Custom Field block to the opt-in form editor for collecting free-text and multi-line answers into subscriber custom data at signup.
The Page After the Click Is Part of Your Brand Too
Broadcast 2.8 adds per-state confirmation page text for all six outcomes and an After Confirmation redirect URL so subscribers can land on your own page instead.
A Segment With a Hardcoded Date Is a Segment That Rots
Broadcast 2.6 adds relative date values (N days ago) to segment rules, so date-based segments stay current automatically instead of needing manual edits.
Connecting an Email Provider Should Not Take an Afternoon
Broadcast 2.1 introduced guided connection wizards for Postmark, AWS SES, SendGrid and Mailgun, with automatic domain and sender discovery plus webhook registration.
What Broadcast 2.0 Actually Changed
A look back at what shipped in Broadcast 2.0: Autopilot AI newsletter drafting, an agent-native surface, API rate limiting, editor improvements, and per-broadcast unsubscribe control.
E2E Email Provider Testing in Rails CI: Verifying Emails Actually Arrive
A technical deep-dive into building end-to-end email provider tests that verify actual email delivery in CI pipelines.
Building Self-Hosting Rails Applications: Design Decisions & Why
Technical deep-dive into the design decisions that make Broadcast a truly self-hostable Rails application.
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