How it works
Postmark splits transactional and broadcast (bulk) email into separate message streams, and broadcasts go out from separate IP addresses, so a newsletter never slows down or taints a login code. It offers an API and SMTP, templates with shared layouts, 45 days of full message history by default, detailed bounce data, inbound email turned into JSON and sent to a webhook, and public delivery-time statistics.
It is known for strict rules: it does not accept purchased lists or cold outreach, and a new account can only email addresses on its own domain until Postmark approves it. ActiveCampaign has owned it since 2022. Plans are priced by monthly volume rather than by contacts, with no daily sending limit.
Postmark pros and cons
Pros
- Strong focus on getting app emails delivered quickly
- Transactional and bulk email kept on separate streams
- Clear logs and 45 days of message history by default
- Helpful docs, templates and inbound email handling
Cons
- Costs more per email than SES or Resend at higher volumes
- The free plan's 100 emails a month only suit testing
- Strict content rules rule out cold email and bought lists
When to use Postmark
Pick it when
- Login codes, password resets and receipts must arrive within seconds
- You want transactional and marketing email clearly separated
Skip it when
- Very high volume, where price per email decides
- Cold outreach or bought lists, which it does not allow
Postmark pricing
Free tier
Free Developer plan with 100 emails a month for testing. Basic starts at $15 a month for 10,000 emails (extra $1.80 per 1,000); Pro starts at $16.50 and Platform at $18.
Postmark pricing page (opens in a new tab)Approximate, checked September 2026.What the other tools cost