Aslio vs Postmark
Aslio vs Postmark — for people watching the bill.
Postmark's reputation is deliverability and restraint, and it is deserved. It is also a premium product with a monthly plan. If the plan is the part that does not fit, this is the comparison.
In short
Aslio is a Postmark alternative billed per message — about $0.21 per 1,000 emails (₹0.02 each) with no monthly plan, no seat charge and no minimum. Postmark is a premium transactional-email specialist with a long deliverability record, strong support and mature tooling. Aslio suits teams whose volume is small, uneven or price-sensitive; Postmark suits teams for whom inbox placement is worth paying a premium for.
- $0.21
- per 1,000 emails
- ₹0
- monthly platform fee
- 0
- seats to buy
- EU
- app hosted in Frankfurt
Side by side
Side by side
Aslio's numbers are exact. Postmark's plans are not reprinted here — they change, and quoting a stale price would be dishonest. Check theirs and compare against ours.
| Postmark | Aslio | |
|---|---|---|
| Pricing model | Monthly plans by volume | Prepaid wallet, per message |
| Cost per 1,000 emails | See postmarkapp.com/pricing | ₹20 — about $0.21 |
| Monthly fee | Yes | None |
| Minimum commitment | Monthly plan | None |
| Deliverability reputation | Excellent, and the core of the product | Good — your own domain and DKIM, suppression enforced before billing |
| Separate transactional / broadcast streams | Yes, a genuine strength | Transactional and batch sends on one API |
| SMTP relay | Yes | Yes — port 587, STARTTLS, API key as password |
| Delivery events | Yes | Yes, every account, from message one |
| Idempotent retries | You handle it | `Idempotency-Key`, enforced by a unique index |
| Refund on permanent failure | You reconcile it | Automatic wallet credit |
| Certifications | SOC 2 | None — stated plainly |
| Support | Widely regarded as excellent | 09:30–18:30 IST, direct to the engineers |
What you get
What you get either way
None of this is gated behind a higher tier on Aslio.
Idempotency that holds
Send with an Idempotency-Key and retry as often as you like. A duplicate replays the original response instead of sending twice — enforced by a unique index, not a check-then-write race.
Refunded when we fail
If a message is charged and then permanently fails, the wallet is credited back automatically and the key is released so your retry can succeed.
Suppression before billing
Hard bounces and complaints go on your do-not-mail list. Later sends to that address are rejected before you are charged, which protects your sender reputation and ours.
One-click unsubscribe
Marketing sends carry RFC 8058 headers, so Gmail and Yahoo show a native Unsubscribe button — required for bulk senders since 2024.
Delivery pushed to you
Sent, delivered, bounced and complained events arrive on your statusCallbackUrl webhook, on every account from the first message.
Your own sending domain
You verify your domain and sign with your own DKIM, so your reputation stays yours instead of being pooled with every other sender on a shared IP.
Honestly
When Postmark is the better choice
- Inbox placement is worth a premium to you. Postmark's deliverability record is the product, and for password resets and receipts that is a rational thing to pay for.
- You want transactional and broadcast strictly separated at the infrastructure level. Postmark's message streams do this properly.
- You need SMTP. Postmark offers a relay; Aslio does not.
- You value support quality above price. Postmark's support has an excellent reputation and a team the size of ours cannot match its coverage.
- Your procurement requires SOC 2. We do not have it.
FAQ
Frequently asked questions
Is Aslio cheaper than Postmark?
Generally yes, and often by a lot — Aslio has no monthly plan at all and charges about $0.21 per 1,000 emails. Postmark is a premium product priced accordingly. Whether that is the right trade depends on how much inbox placement is worth to you, which is a real question rather than a rhetorical one.
Will deliverability be worse?
We are not going to claim we match Postmark's record, because deliverability reputation is earned over years. What Aslio does structurally: you send on your own verified domain with your own DKIM, so reputation is yours rather than pooled, and hard bounces and complaints are suppressed automatically before you are charged again.
Does Aslio separate transactional and marketing sends?
They share one API, but marketing sends carry RFC 8058 one-click unsubscribe headers and suppression applies across both. Postmark's dedicated message streams are a stronger separation, and if that matters to you it is a genuine reason to stay.
Can I move gradually?
Yes, and you should. Send a slice of low-risk traffic — internal notifications, non-critical alerts — through Aslio first and watch the delivery events before moving anything a customer depends on.
What does Aslio do that Postmark does not?
Two things concretely: idempotent retries enforced by a unique index rather than left to you, and automatic wallet refunds when a charged message permanently fails. Neither is glamorous; both remove reconciliation work.
Run both in parallel. Keep the one that wins.
Top up a wallet and send. No monthly platform fee, no seat charge, no minimum commitment — a hundred test emails costs about one rupee.
Asli One Global Private Limited · CIN U62011TN2026PTC190105