EmailEngine vs Postmark (2026): which should you pick?

Pick EmailEngine if

• Fits if you're building an app that has to read and send from your users' own mailboxes
• Works for teams with many mailboxes who want one flat price and can run a server

Look elsewhere if

• Skip it if you want a hosted service, because you run it yourself and there isn't one
• Pricey if you have only a few mailboxes, as the price is the same $1,450 a year for any number
• Not for you if you want open source: it's source available and needs a subscription past the trial
• Watch out: it needs a Redis database that persists data
• Watch out: prices leave out VAT

Pick Postmark if

• Fits if you want password resets kept on a separate stream from your newsletters
• Works for apps that need to look back at exactly what an email said weeks later

Look elsewhere if

• Pricey if you send 50,000 emails a month, at $55 with no yearly discount
• Skip it if you want a free plan to run a small app on, as it's 100 emails a month with no tier until 10,000
• Tight if you're on Basic, with 4 users, 5 sending domains and no inbound email
• Not for you if you want a dedicated IP below 300,000 emails a month, and each one is $50 a month on Pro or higher
• Watch out: DMARC reports are an add-on from $14 a month per domain

EmailEngine

• It is source available rather than open source: running it beyond the trial requires a subscription.
• You host it yourself and it needs a Redis database that must persist data.
• The flat price is $1,450 a year ($199 a month) whatever the mailbox count, so it suits larger use more than a few mailboxes.
• Prices exclude VAT, and the vendor lists the product's platforms as Linux, macOS, Windows and Docker with no hosted version.

Postmark

• There is no tier between the free 100 emails a month and the 10,000-email paid plans.
• Billing is monthly only; the FAQ says annual plans are not offered yet.
• Basic has no inbound email processing and caps users at 4 and sending domains at 5.
• Dedicated IPs start at $50 a month per IP, need Pro or higher and 300,000 emails a month or more.

EmailEngine

One REST API for three mailbox types

Read, send and sync Gmail, Microsoft 365 and generic IMAP accounts through the same API.

Webhooks for incoming mail

New messages in a connected mailbox are pushed to your application as parsed JSON, so the app does not poll or speak IMAP.

Managed OAuth2

Handles OAuth2 for Microsoft 365 and Google Workspace, and can bridge legacy apps that only speak IMAP and SMTP.

Self-hosted deployment

Ships as a single binary, a Docker image, an npm package and an installer script, and needs a Redis database.

Agent access

The same API is offered as a tool surface for AI agents that read, summarize, draft and send mail.

Postmark

Email API and SMTP

Send through a REST API with official SDKs or through SMTP, with batch sending, a sandbox mode and migration guides from other providers.

Message streams

Transactional and bulk or broadcast email run on separate sending infrastructure, so marketing sends do not affect password resets and receipts.

Inbound email processing

Pro and Platform turn incoming email into a JSON object and post it to a webhook URL your app handles.

Templates

Responsive templates for welcome emails, password resets and receipts, with a template editor and import tool.

Message history and analytics

45 days of full message content by default, adjustable from 7 to 365 days, with bounce details, open and link tracking and a stats API.

DMARC monitoring

DMARC Digests reports show authentication problems and who is sending with your domain, sold as an add-on from $14 a month per domain.

EmailEngine

• Subscription$1,450

  per year, unlimited mailboxes ($199 billed monthly)

  Unlimited mailboxes, instances, API calls, webhooks and licence keys, plus updates while subscribed. In euros: €1,200 a year or €169 a month; VAT extra.

• EnterpriseCustom

  The same software with a perpetual licence paid once, offline verification, invoice or wire payment, net terms and custom contract terms.

Postmark

• Free$0

  100 emails a month, never expires; extra emails cannot be bought on this plan.

• Basic$15

  per month for 10,000 emails

  5 sending domains, 4 users, 45 days of history, no inbound email. Extra emails $1.80 per 1,000; $55 a month at 50,000 emails.

• Pro$16.50

  per month for 10,000 emails

  10 domains, 6 users, inbound email, retention up to 365 days. Extra emails $1.30 per 1,000; $60.50 a month at 50,000 emails.

• Platform$18

  per month for 10,000 emails

  Unlimited domains, servers, streams and users, with inbound email. Extra emails $1.20 per 1,000; $66 a month at 50,000 emails.

• High volumeCustom

  Custom pricing for large senders, arranged through sales.

EmailEngine

No public discounts listed.

Postmark

• Startups

  $75 credit for bootstrapped companies

  Companies that have launched, are charging for their product and have taken no outside investment can ask support for $75 of account credit.