Self-hosted email deliverability
Deliverability is the number-one worry for anyone running their own email platform—and the most common reason people hesitate to leave hosted SaaS. The good news: when you self-host, your sender reputation is yours to build and protect, not shared with thousands of strangers. This guide is the full playbook, from authentication to the inbox.
The one thing to understand: deliverability is not magic the platform does for you—it’s the long-term state of your domain and IP reputation, built from consistent authentication, list hygiene, and engagement. Self-hosting doesn’t make this harder; it makes it yours. You connect a proven email provider (SES, Postmark, Mailgun, or any SMTP), and the reputation you build belongs to your domain—not a SaaS you share with spammers.
The deliverability stack
Work through these in order. Each links to a focused guide or free tool.
Authenticate: SPF, DKIM, DMARC
The three DNS records that prove you’re allowed to send for your domain. Non-negotiable in 2026.
Choose your email provider
Self-hosting separates the app from the sender. Pick the relay that fits your volume and budget.
Warm up your domain & IP
New senders start at zero reputation. Ramp volume gradually so mailbox providers learn to trust you.
Test before you send
Check authentication and content before a big send, then monitor placement over time.
Handle bounces & complaints
List hygiene protects your reputation. See the section below for the thresholds that matter.
Meet Gmail & Yahoo rules
The 2024 bulk-sender requirements are now table stakes. See the checklist below.
Bounces & complaints: the thresholds that matter
Mailbox providers and your ESP both watch how cleanly you send. Cross the wrong line and your sending gets throttled or suspended—Amazon SES, for example, will pause an account whose rates climb too high.
Hard bounces
Permanent failures (the address doesn’t exist). Remove these immediately and never email them again. Aim to keep your hard-bounce rate under 2%—a high rate signals you’re mailing a stale or purchased list.
Soft bounces
Temporary failures (full mailbox, server down). Retry a few times, then suppress the address if it keeps failing. Don’t keep hammering a soft-bouncing address—it looks like spammer behaviour.
Spam complaints
When someone hits “report spam.” Keep this below 0.1%; Gmail and Yahoo now expect you to stay under 0.3% and ideally never spike above 0.1%. Wire up feedback loops (and SES complaint notifications via SNS) so complaints auto-suppress.
Broadcast handles unsubscribes automatically and surfaces bounce and complaint analytics, so you can act on these signals without building the plumbing yourself.
The Gmail & Yahoo bulk-sender checklist
Since February 2024, Gmail and Yahoo enforce requirements on anyone sending more than ~5,000 messages a day to their users. These are now the baseline for reaching the inbox at any real volume.
-
Authenticate with SPF, DKIM, and DMARC. All three, on your sending domain. DMARC can start at
p=none, but it must exist. -
One-click unsubscribe. Include a
List-Unsubscribeheader and honour opt-outs within two days. - Keep spam complaints under 0.3%. Treat 0.1% as your real ceiling; above it, expect throttling.
-
Align your domains. Your
Fromdomain should align with SPF or DKIM, and you need valid forward and reverse DNS (PTR) on your sending IP. - Send wanted mail to engaged people. The simplest, most durable deliverability strategy there is.
Using an established ESP (SES, Postmark, Mailgun) covers the infrastructure side—PTR records, TLS, RFC-compliant formatting—so you focus on authentication, hygiene, and engagement.
Stuck on a deliverability problem?
If you’re already in the spam folder and need to recover, sometimes it’s worth bringing in a specialist. Here’s how to think about it.
Own your sending reputation
Broadcast runs on your server and your chosen ESP—your IP, your domain, your reputation. With automatic unsubscribe handling and deliverability analytics built in.
