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Home/Compare/Postmark vs Customer.io

Postmark vs Customer.io

A side-by-side comparison of pricing, plans, and recent product updates. Pricing data last refreshed May 14, 2026.

Postmark

Reliable transactional email.

Visit →
Category
email
Plans tracked
4
Entry price
$15/mo
Free plan?
Yes
See full Postmark pricing & changelog →

Customer.io

Messaging automation for lifecycle and product email.

Visit →
Category
email
Plans tracked
—
Entry price
—
Free plan?
—
See full Customer.io pricing & changelog →

Plan-by-plan pricing

Postmark

Free

Postmark

Free
  • Test your integration with 100 emails/month
  • No overages allowed in this plan
  • Perfect for testing and side projects with low volume
  • Up to 10 custom sending domains
  • Up to 10 servers
  • + 1 more

Basic

Postmark

$15/mo
  • Extra emails @ $1.80 / 1,000
  • Industry-leading deliverability rates & speed
  • 45-day data retention
  • 5 Custom sending domains
  • Unlimited emails/day
  • + 1 more

Pro

Postmark

$16.5/mo
  • Extra emails @ $1.30 / 1,000
  • Customizable data retention up to 365 days (45-day default)
  • 10 Custom sending domains
  • Inbound email processing
  • Unlimited emails/day
  • + 1 more

Platform

Postmark

$18/mo
  • Extra emails @ $1.20 / 1,000
  • Customizable data retention up to 365 days (45-day default)
  • Unlimited Custom sending domains
  • Inbound email processing
  • Unlimited users
  • + 1 more

Customer.io

Pricing data is being collected.

Postmark vs Customer.io FAQ

Postmark vs Customer.io: which is cheaper?
Postmark starts at $15/mo, while Customer.io starts at an unpublished tier. TrackRival snapshots both daily as plan pages change.
Does Postmark or Customer.io have a free plan?
Postmark shows a free plan in the latest snapshot, while Customer.io does not.
Is Postmark a good email alternative to Customer.io?
Postmark and Customer.io are both tracked in TrackRival's email category. Use the changelog section below to compare shipping cadence, not just headline pricing.
How often is this Postmark vs Customer.io comparison updated?
TrackRival refreshes pricing snapshots daily and appends new changelog entries whenever either product ships a release.

Which should you pick?

Both Postmark and Customer.io compete in the email space.

  • Choose Postmark if you value: reliable transactional email.
  • Choose Customer.io if you value: messaging automation for lifecycle and product email.
  • Subscribe to TrackRival if you want to be notified whenever either of them changes pricing or ships a major update — so you can react before your competitors do.

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