Listmonk vs Sendy vs MailWizz: Which One Won't Get You Suspended?

Every "best self-hosted newsletter" roundup ranks these three on features: templates, autoresponders, price. That's the wrong axis. The question that decides whether your list survives the next Amazon SES suspension is not who has prettier reports — it's what happens when bounces spike while you're not looking.

The documented failure pattern: SES pauses an account over a bounce-rate spike after a sending pause, rejects the appeal, and 5,000 subscribers worth roughly $1k/mo in newsletter revenue go dark. If your migration question is "which self-hosted app," start with the bounce-handling machinery, because that's the thing that kills lists.

The one comparison that matters: bounce handling

The facts, axis by axis — the row label is the comparison dimension, the three entries are Sendy / MailWizz / Listmonk:

Rail lock-in. Amazon SES only — dies with the SES account / any SMTP or delivery server / any SMTP or delivery server.

Bounce feedback. SES SNS notifications / bounce servers (POP3/IMAP) plus webhooks / provider bounce webhooks (Settings → Bounces).

What a bounce does. Marks the subscriber bounced per list / marks or suppresses per rules / marks the subscriber per rules.

Failover if your rail dies. None — no second rail possible / can queue across multiple delivery servers / manual provider swap.

List export (full, CSV). Yes / yes / yes (SQL-level, full control).

Source. Closed, one-time license ($69); major-version upgrades cost again / closed, one-time license ($99); major-version upgrades cost again / open source — inspect every bounce path.

Sendy: great until SES notices you

Sendy is the default recommendation for a reason: $69 once, clean reports, brands, autoresponders, and SES's $1-per-10,000-message sending cost. Its bounce handling is actually solid for the happy path — SES SNS feedback flows in, bounced addresses get suppressed, your list stays clean.

The structural problem is the SES lock-in. If your SES account is paused (bounce spike, account review, appeal denied), Sendy has no plan B: it can only send through SES. Your software is fine; your ability to reach your list is gone. And Sendy's one-time license didn't extend to the next major version — owners paid again. The "buy once, own forever" story has asterisks.

Pick Sendy if: you're on SES, your sending is steady and warmed, your bounces are already under control, and you're optimizing cost per thousand emails.

MailWizz: the deliverability geek's pick — with real bounce plumbing

MailWizz is the oldest of the three and it shows in the bounce machinery. It supports bounce servers — dedicated POP3/IMAP inboxes that receive and process bounce messages from any provider — plus webhook-based feedback. Unlike Sendy, it's rail-agnostic: SES, any SMTP, multiple delivery servers with per-server allocation. If one delivery server fails, campaigns can route to another. That's real failover, not a marketing word.

The cost: $99 one-time (CodeCanyon Regular license, 2026), dated UI, a steeper learning curve, and closed source. You trust MailWizz's bounce parsing; you can't inspect it the way you can with open source.

Pick MailWizz if: you run multiple sending providers, you want genuine delivery-server failover, and you don't mind closed-source software doing the bounce parsing.

Listmonk: free, open, and honest about what it is

Listmonk is the only open-source option of the three, and the only one that runs as a single binary with a real Postgres (or SQLite) database. Bounce processing is first-class: Settings → Bounces → enable processing and provider webhooks (SES included, documented step-by-step). Since you own the database, a full list export is a SQL query — the "can I ever be taken off these rails" question has the strongest answer here.

The honest catch: Listmonk is provider-agnostic but not a failover engine. If SES pauses you, Listmonk keeps working — but you have to point it at another provider yourself, and bounce-handling configuration is on you per provider. "Won't get you suspended" here means: no single vendor can hold your list hostage.

Pick Listmonk if: you want zero licensing cost, inspectable bounce handling, and absolute data ownership — and you're comfortable configuring one provider at a time.

So which one won't get you suspended?

Blunt truth: none of them prevent a suspension. Suspensions come from the sending rail (SES's bounce/complaint tripwires), not from the app. What the app controls is your blast radius:

• Sendy: smallest blast radius problem — largest. One rail, one point of failure.
• MailWizz: best built-in blast-radius control — multi-rail failover out of the box.
• Listmonk: best ownership — no vendor can take your list or your tooling away.

Ranked by "which one survives the morning SES kills your account": MailWizz keeps sending through rail #2 the same morning. Listmonk survives intact and moves providers on your schedule. Sendy waits with you.

That ranking is why the migration conversation shouldn't end at "which app." The people who survive rail kills are the ones who (1) export their list constantly (full, clean CSV — non-negotiable), (2) keep a second sending provider configured and warmed, and (3) treat bounce handling as infrastructure, not a feature. Whatever app you pick, do those three things this week.

Next step: grab the free deliverability self-audit checklist and check your list against the SES tripwires before the next send. It takes 15 minutes, and it's the check that would have saved that 5,000-subscriber list.