Postmark vs MailerSend
Deliverability-first transactional email versus API plus drag-and-drop template builder.
What matters for growth and lifecycle teams
Growth work lives or dies on targeting and measurement. What matters is whether behavioral triggers can be built without engineering time, whether the event stream supports attribution past the open, and whether deliverability holds when broadcast volume shares a reputation with product email.
| Priority | Postmark | MailerSend |
|---|---|---|
| Scheduling | No | Yes |
| Event stream | Yes | Yes |
| Deliverability | Strong transactional reputation with separate streams for transactional and broadcast traffic, which helps protect sender reputation. | Good and steadily improving; reputation managed via dedicated IP options on paid plans. |
| Operating since | 2010 | 2020 |
| Suppressions API | Yes | Yes |
| Best published rate per 1,000 | $1.50 | Tiers not published in comparable form |
| Multi-tenant | Yes | Yes |
| Free tier | 100/mo developer plan | 500/mo permanent |
| Starts at | $15/mo for 10,000 emails | $7/mo for 5,000 emails |
For lifecycle and activation work running behavior-triggered journeys, broadcasts, and winback campaigns measured on revenue, the split is even: Postmark takes operating track record, MailerSend takes scheduling. Neither pulls ahead on this audience's priorities. On free tier, Postmark offers 100/mo developer plan against 500/mo permanent from MailerSend. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Postmark | MailerSend |
|---|---|---|
| Deliverability | Strong transactional reputation with separate streams for transactional and broadcast traffic, which helps protect sender reputation. | Good and steadily improving; reputation managed via dedicated IP options on paid plans. |
| Multi-tenant | Yes | Yes |
| Free tier | 100/mo developer plan | 500/mo permanent |
| Starts at | $15/mo for 10,000 emails | $7/mo for 5,000 emails |
| Tagline | Transactional-only, fast and well-delivered. | Modern transactional API with a clean UI. |
| Pricing model | tiered | tiered |
| API | Yes | Yes |
| SMTP | Yes | Yes |
| SDKs | node, python, go, ruby, php, java, elixir, rust, dotnet | node, python, go, ruby, php |
| Templates | rich | rich |
| React Email | No | No |
| Webhooks | Yes | Yes |
| Inbound | Yes | Yes |
| Idempotency | No | No |
| Dedicated IP | Yes | Yes |
| DX score | 9/10 | 8/10 |
| Best for | Teams where password resets, receipts, and magic links absolutely cannot miss the inbox. | Teams that want both API and visual template editing. |
Postmark
- ›Transactional-only routing and strong operational history
- ›Streams cleanly separate transactional and broadcast
- ›Free DMARC monitoring product (dmarc.postmarkapp.com)
- ›Retains full message content and metadata for 45 days for debugging
- ›No idempotency keys
- ›Pricing per email is higher than SES, Mailgun, or SMTP2GO
- ›No drag-and-drop template builder
- ›Marketing automation is intentionally absent
MailerSend
- ›Drag-and-drop templates plus API
- ›Inbound routing supported
- ›Sub-accounts for agencies
- ›Smaller SDK footprint than SendGrid
- ›Brand and ecosystem less recognized than older providers