Postal vs listmonk
Both are alternatives to SendGrid. Here's how they stack up — verified facts, no spin.
Also searched as listmonk vs Postal — same comparison, one verdict.
Postal and listmonk are closely matched on ownership (94 vs 93) — this one comes down to pricing and to which trade-offs below you can live with.
Postal
Run your own mail server, properly — MIT, and complete.
Postal is a full self-hosted mail platform: sending, receiving, bounce handling, click and open tracking, DKIM signing and a web interface — the parts you would otherwise assemble from Postfix, OpenDKIM and a database. MIT, around 17k stars. It is the only option here where addresses never leave your infrastructure, which for GDPR-sensitive senders is not a preference but a requirement. The honest warning: running a mail server well is a real discipline, and reputation is unforgiving of mistakes.
listmonk
Self-hosted newsletters — a single binary handling millions.
listmonk is a self-hosted newsletter and mailing-list manager: subscriber management, segmentation, templates, analytics and bounce processing, as one Go binary with Postgres behind it. AGPL-3.0, around 23k stars, and documented as handling millions of subscribers on modest hardware. It is not a transactional sender — it hands off to SES or your own SMTP — which makes it a complement rather than a competitor. For anyone paying Mailchimp per subscriber for a newsletter, this removes that bill entirely.
Side by side
10 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Postal | listmonk | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 94 | 93 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | MIT | AGPL-3.0 |
| Pricing | Free and open source. You supply the server and the IP reputation. | Free and open source. You pay only for the underlying sending. |
| RAM to run it wellThe figure that actually matters, not the vendor's minimum. | — | 1 GB |
| Realistic running costWhat the box costs each month if you run it yourself. | — | $6/mo plus SMTP relay costs, against Mailchimp pricing that scales per subscriber |
| Setup timeHonest first-install estimate, not the marketing quickstart. | — | 1 hour for the app, plus the real work below |
| Ongoing maintenanceThe part nobody budgets for. | — | Low for the app. Deliverability is the ongoing job. |
Postal edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Weighing both against staying on SendGrid? Is SendGrid free? What it actually costs →
Postal
Strengths
- +MIT with no enterprise carve-out
- +Recipient addresses never leave your infrastructure
- +Full platform — sending, receiving, bounces, tracking, DKIM
- +No per-email cost at any volume
Trade-offs
- −You own IP reputation, and warming takes weeks of care
- −Running mail well is a genuine specialism
- −Blocklists are unforgiving of configuration mistakes
- −No shared warmed pool to fall back on
listmonk
Strengths
- +Removes per-subscriber pricing entirely
- +One Go binary plus Postgres — genuinely simple to run
- +Handles very large lists on modest hardware
- +Subscriber data stays on your infrastructure
Trade-offs
- −Not a transactional sender — pairs with SES or your own SMTP
- −AGPL-3.0 needs reading before embedding it in a product
- −No shared IP reputation; deliverability is yours
- −Fewer templates than the commercial platforms
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Postal
if a lower exit cost matters more to you than any single feature, and mIT with no enterprise carve-out.
Choose listmonk
if removes per-subscriber pricing entirely.
Neither, yet
if both carry a real cost you should weigh first — you own IP reputation, and warming takes weeks of care, and not a transactional sender — pairs with SES or your own SMTP. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
What it takes to run these yourself
Real requirements and honest running costs, not the vendor quickstart.
Postal vs listmonk — common questions
Is Postal a better fit than listmonk for transactional & bulk email?
It depends on what you are optimising for, and the honest split is this: Postal scores 94 to listmonk's 93 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. listmonk earns its place on a different axis — removes per-subscriber pricing entirely. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Postal keeps its data local or in open formats, so leaving is an export rather than a negotiation. listmonk is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host Postal or listmonk?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are Postal and listmonk both alternatives to SendGrid?
Yes — both appear in our SendGrid comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off SendGrid and now choosing between the two replacements, which is a narrower and much easier question.
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Facts verified 2026-09-27. Licenses and pricing change — spotted something out of date? That's a correction we want.