We're changing how email is priced.

One fixed monthly price per cluster, sized for your busiest hour and rolling 24 hours. No per-email overages and no per-domain fees.

Start free trial Why PostShiba?

Cluster plans

Available in beta

Nano

$5 a month

100 emails / hour

Micro

$15 a month

4k emails / hour

Small

$49 a month

40k emails / hour

Medium

$99 a month

100k emails / hour

Large

$299 a month

200k emails / hour

Unavailable during beta

XL

$599 a month

400k emails / hour

Burst

$1,499 a month

800k emails / hour

At the hourly or rolling 24-hour cap, REST returns 429 throttled, HTTP inject returns 429 send limit reached, and SMTP returns 451 send limit reached. Spread large sends over time.

Boost a busy day.

Available in beta

Variable price

A temporary boost to your cluster's capacity. It adds 24 hours of outbound sending on top of your plan.

Outbound, next 24 hours

Add sending IPs.

Additional shared IPs

$15 a month

Extra shared sending IP. Every cluster already includes 1 shared IP.

Shared IPs
Extra
  • 198.51.100.24 Included
  • 198.51.100.37 +$15/mo
  • 198.51.100.52 +$15/mo

Additional dedicated IPs

$50 a month

Exclusive sending IP. Pick it from Network in the dashboard.

Network Same class as your cluster

Receive email.

Receiving

Free, no charge per message

Mail to your inboxes has no per-message charge, whether you take it by webhook, forwarding, or the API.

Delivery Every inbox
  • Webhook Posted to your URL as it arrives
  • Forwarding Sent on to an address on your domain
  • REST API Listed and fetched when you ask

Per message received $0.00

Inbox storage

$0.50 per GB-month

You pay for the average stored over the month. Mail leaves storage when your webhook takes it or when it expires.

Inbox storage

Estimate your plan.

Nano: $5/month estimated
Where PostShiba starts costing less.
Monthly bill by email volume: PostShiba against Postmark At 1,000,000 emails a month spread evenly, PostShiba Small costs $49 and Postmark costs $775.
1,000,000 ≈ 1,389 an hour · 33,334 a day, spread evenly
Postmark
$775
Basic 1.5M
PostShiba
$49
Small · 40,000/hr · 240,000/24h
At this volume
Save $726 a month
94% less than Postmark. PostShiba costs less at every volume shown.

Assumes sends are spread evenly across the month, the way PostShiba capacity is meant to be used. Bursty senders should size for their busiest hour. Competitor bills use USD list prices from public pricing pages, September 2026, before tax and add-ons. Postmark: Basic tier committed volume steps, plus Basic overage.

Included with every cluster.

  • One shared-IP sending environment
  • Multiple sending domains with no per-domain charge
  • Shared sending pools with reputable neighbors
  • SMTP, HTTP inject, and the REST API
  • Free inbound email
  • Helpful resources and support
  • The first cluster includes 7 days free

No overage bills.

Postmark, Resend, and other usage-billed providers charge for every spike. PostShiba returns 429 at your cap, so you retry later and the bill stays the same.

What a sign-up attack costs.
What a sign-up attack costs. Bot sign-ups trigger confirmation emails. The usage-billed bill climbs to $960. PostShiba stays at the $15 Micro capacity price and throttles the excess with 429. PostShiba $15/mo 429 throttled, retry later
  • Usage-billed provider $960
  • PostShiba $15/mo Micro
Illustrative bills, not list prices

Postmark, Resend, and others

Every extra send is billed. A traffic spike becomes an overage invoice.

PostShiba

REST and HTTP inject return 429 throttled. SMTP waits in queue. Same monthly price, no surprise bill.

Start free trial

Bring your own cloud.

Enterprise BYOC runs capsules in your cloud account, with custom pricing through sales.

New message Enterprise BYOC
To
jesse@postshiba.com
Subject
Enterprise BYOC

Before you start.

Can I use multiple sending domains?

Yes. Add multiple sending domains to one account without a per-domain charge. Verify each domain before sending. Messages across those domains share your chosen cluster's capacity.

Set up a sending domain
What limits sending during beta?

Plan capacity is the sending limit during beta. Size your cluster for the busiest hour and the rolling 24 hours.

How do invitations and production approval work?

Start by requesting beta access. After signup, create your first cluster, verify a domain, and test with your team's email addresses. Request production approval from the dashboard and tell us how you plan to use PostShiba.

We review accounts individually before opening sending to external recipients. There is no fixed invitation or approval timeframe during beta, so wait for approval before scheduling your migration.

How production approval works Start free trial
Is there a trial, and do I need a card?

Your first cluster includes 7 days free. Add a payment method before creating it. The trial is tied to your first cluster's subscription and runs separately from production approval. The selected monthly plan applies after the trial.

Which plans can I start with?

New clusters can choose Nano (100 / hour · 600 / 24h), Micro (4,000 / hour · 24,000 / 24h), Small (40,000 / hour · 240,000 / 24h), Medium (100,000 / hour · 600,000 / 24h), and Large (200,000 / hour · 1,200,000 / 24h) during beta. Choose for your busiest hour and the rolling 24 hours, including spikes. If your workload needs more, contact us before moving production traffic.

Estimate your plan
What happens during a traffic spike?

Requests over the hourly or 24-hour sending cap return 429 on REST and 451 on SMTP. Your app must retain rejected messages and retry when capacity is available. Size your plan for peak traffic so urgent mail is not delayed.

What happens at your cap
How do I get help?

Email jesse@postshiba.com for setup, migration, or sending questions. For a delivery investigation, include the message ID and sending domain. If you need specific support coverage, discuss it with us before migrating.

Try your first cluster free for 7 days.

Pick a plan, verify a domain, and test with your team while production approval is pending.

Start free trial Why PostShiba?