Postmark
Transactional email API focused on inbox placement and detailed delivery analytics.
Postmark is a transactional email API built around fast, reliable delivery for receipts, password resets, and system notifications. It runs separate infrastructure for outbound and inbound mail, exposes detailed bounce and open analytics, and offers customizable retention up to 365 days for compliance use cases. All paid tiers start at the same 10,000 emails/month volume; differentiation is feature scope (custom domains, retention window, inbound) and per-1,000 overage rate. Owned by ActiveCampaign since 2022 but operated as a separate product.
- Category
- Transactional email
- Free plan
- Yes
- Plans
- 5
- Verified
Plans & pricing
Headline prices for each Postmark tier, captured from https://postmarkapp.com/pricing on .
Free
100 emails per month, no credit card required
- Emails / month
- 100
- Team seats
- ·
- Custom domains
- Custom
Included
- 100 emails per month
- No credit card required
- Never expires
- Outbound and inbound APIs
- Basic delivery analytics
Not on this plan
- Overage sends (account pauses at 100)
- Custom retention window
- Multiple custom domains
- Unlimited daily send caps
- Full analytics suite
No overages allowed; sending pauses if you hit the cap.
Basic
Entry paid tier with 10,000 emails/month and 5 custom domains
- Emails / month
- 10,000
- Team seats
- ·
- Custom domains
- 5
Included
- 10,000 emails/month included
- $1.80 per 1,000 overage
- 5 custom domains
- 45-day data retention
- Unlimited daily sends
- Delivery analytics
Not on this plan
- Customizable retention up to 365 days
- Inbound email processing
- 10 custom domains
- Unlimited custom domains
- Unlimited users
- Full analytics suite
Pro
10,000 emails/month with inbound processing and customizable retention
- Emails / month
- 10,000
- Team seats
- ·
- Custom domains
- 10
Included
- 10,000 emails/month included
- $1.30 per 1,000 overage
- 10 custom domains
- Customizable retention up to 365 days
- Inbound email processing
- Unlimited daily sends
- Delivery analytics
Not on this plan
- Unlimited custom domains
- Unlimited users
- Full analytics suite
- $1.20 per 1,000 overage rate
Platform
Unlimited domains and users with the lowest overage rate
- Emails / month
- 10,000
- Team seats
- Unlimited
- Custom domains
- Unlimited
Included
- 10,000 emails/month included
- $1.20 per 1,000 overage
- Unlimited custom domains
- Unlimited users
- Customizable retention up to 365 days
- Inbound email processing
- Unlimited daily sends
- Full analytics suite
Not on this plan
- Custom contracting for high-volume senders
- Negotiated rates above standard tiers
High-Volume
Custom pricing for volumes above standard tiers
- Emails / month
- Custom
- Team seats
- Unlimited
- Custom domains
- Unlimited
Included
- High-volume send capacity
- Custom contracting and negotiated rates
- Unlimited custom domains
- Unlimited users
- Full analytics suite
- Inbound email processing
- Customizable retention
Where Postmark earns its price
- Industry-leading deliverability reputation, the core of Postmark's pitch and verified by independent inbox-placement tests
- Separate inbound and outbound infrastructure means receiving mail never competes with sending throughput
- Customizable retention up to 365 days on Pro and Platform tiers supports compliance and audit use cases
- Transparent overage pricing at $1.80, $1.30, and $1.20 per 1,000 emails across paid tiers
- Unlimited daily send caps starting at $15/month; Mailgun's similar entry tier enforces a daily cap
Where it falls short
- Free tier is only 100 emails/month total, much smaller than Mailgun's 100/day or Resend's 3,000/month
- Paid plans all start at the same 10,000-email threshold, so differentiation is feature-only at small volumes
- Pricing scales for high-volume senders only via the custom High-Volume tier rather than published rates
- Ownership by ActiveCampaign creates roadmap uncertainty for some buyers
Best for
- SaaS apps prioritizing receipt and notification deliverability
- Teams that need detailed inbound email parsing alongside outbound sends
- Companies that need 365-day data retention for compliance
Not for
- Hobby projects with bursty traffic (Mailgun's 100/day or Resend's 3,000/month are friendlier than the 100/month Free cap)
- Marketing teams (use Mailchimp or Kit)
- Buyers who want a single vendor for marketing and transactional email
Alternatives to Postmark
Tools we cover in the same space.
Common questions
- Does Postmark have a free plan?
- Yes. Postmark offers a free tier. 100 emails per month, no credit card required
- How much does Postmark cost?
- Postmark starts at Free. Plan prices captured April 30, 2026.
Source: https://postmarkapp.com/pricing · last verified · capture method: manual
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