What is Postmark used for?

Postmark is a transactional email API and SMTP service that developers use to send application email such as receipts and password resets. It is a good fit for password reset and receipt emails, and agencies handling email for client apps.

Yes. Postmark has a free plan. Free developer plan with 100 emails a month. Paid plans start at 10,000 emails a month: Basic $15, Pro $16.50 and Platform $18 per month, with overage billed per 1,000 emails; high-volume pricing is custom.

Is Postmark open source?

No. Postmark is proprietary (closed-source) software and can't be self-hosted. Open-source alternatives to Postmark include Postal, Plunk and Notifuse.

What are some alternatives to Postmark?

Postmark competes with Amazon SES, Resend and MailerSend. For open-source options, see Enlisted's ranked list of open-source Postmark alternatives.

Postmark: features, pricing and alternatives

About Postmark

Postmark is a commercial email delivery service focused on transactional messages, the automated emails an application sends in response to user actions. Developers integrate through an email API or SMTP and rely on the service to get messages to the inbox quickly.

A notable design choice is message streams, which keep transactional email separate from bulk or broadcast sending so each can be managed on its own. The product also includes templates, inbound email handling, analytics and retention of message history, integrations and a bulk API. The vendor publishes comparisons with other email providers and guidance for AI coding agents. Postmark is hosted only.

Key features

Transactional email API
SMTP service for application email
Message streams separating email types
Reusable email templates
Inbound email processing
Delivery analytics and message history

Good fit for

→Password reset and receipt emails
→Agencies handling email for client apps

Tags: transactional-email; email-api; smtp; deliverability; developer-tools; email-delivery; inbound-email

Postmark: questions and answers

What is Postmark used for?: Postmark is a transactional email API and SMTP service that developers use to send application email such as receipts and password resets. It is a good fit for password reset and receipt emails, and agencies handling email for client apps.
Is Postmark free?: Yes. Postmark has a free plan. Free developer plan with 100 emails a month. Paid plans start at 10,000 emails a month: Basic $15, Pro $16.50 and Platform $18 per month, with overage billed per 1,000 emails; high-volume pricing is custom.
Is Postmark open source?: No. Postmark is proprietary (closed-source) software and can't be self-hosted. Open-source alternatives to Postmark include Postal, Plunk and Notifuse.
What are some alternatives to Postmark?: Postmark competes with Amazon SES, Resend and MailerSend. For open-source options, see Enlisted's ranked list of open-source Postmark alternatives.