InboxKit Pricing: Every Price, Cost Tables and the Refund Fine Print

InboxKit pricing is a flat $3 per Google Workspace or Microsoft 365 mailbox a month on monthly billing, or $2.50 a month on annual billing, as of November 2026. Azure costs $30 a month per tenant of up to 100 mailboxes, pre-warmed mailboxes run $6 to $9, and warmup is a $3 add-on. Domains are extra, and InboxKit does not publish its domain price.

For what the product does beyond price, including the policy fine print, read our InboxKit review.

InboxKit pricing at a glance

InboxKit's pricing page sums up the model as "One flat rate. No plans, no base fee, no minimum." The rate does not change with volume, so 10 mailboxes and 1,000 mailboxes cost the same per mailbox.

Very large deployments can ask for custom pricing.

Setup, DNS and admin panels are listed as "Included," and no setup fee appears on the page.

Monthly, quarterly and annual billing

The billing cycle is the only discount InboxKit offers on standard mailboxes.

A 10% discount on $3 would be $2.70, but that is our arithmetic, not an InboxKit figure. InboxKit's own example on the pricing page is 50 mailboxes at $2.50, which is $125 a month, with "You save $300 a year vs monthly."

You can switch billing periods later, and the change takes effect at the next billing cycle.

Why you may see "$3 flat" and "from $2.50"

InboxKit's homepage comparison table says "$3 per mailbox, flat," while the hero says mailboxes start "from $2.50." Both are accurate once you know the cycle: $3 is monthly and $2.50 is the annual rate. Budget on $3 unless you are ready to prepay a year.

What 10, 50 and 100 inboxes cost

These tables are our estimates from InboxKit's list prices, as of November 2026. They cover Google Workspace or Microsoft 365 mailboxes only.

Without warmup

With InboxKit's $3 warmup add-on

The warmup add-on doubles the mailbox bill. That is the main reason to look at your sequencer first: InboxKit's own warmup page says sequencer-based warmup "is included with your sequencer subscription." Instantly, Smartlead and PlusVibe all include warmup in their sending plans; our Instantly review and Smartlead review cover how each one handles it.

If you still want InboxKit's own warmup, you can add it per mailbox in InboxKit.

Pre-warmed mailboxes

Pre-warmed orders also carry one-time domain fees "from $12.50" each. The trade is time: you pay more per mailbox to skip some of the warmup wait.

Sending capacity for the money

At InboxKit's recommended 10 to 15 cold emails per mailbox per day after warmup, 10 inboxes send roughly 100 to 150 cold emails a day, 50 inboxes 500 to 750, and 100 inboxes 1,000 to 1,500 (our arithmetic). Our cold email cost calculator adds domains, data and sequencer costs to these figures.

Azure pricing and the per-mailbox catch

InboxKit sells Azure as "Microsoft 365 mailboxes provisioned on a Microsoft Azure tenant," in tenants of 25, 50 or 100 mailboxes for $30 a tenant a month. On paper, the per-mailbox cost falls fast as you fill the tenant.

The catch is in InboxKit's own sequencer presets, which lower per-mailbox volume as the tenant fills: 20 a day at 10 mailboxes, down to 2 a day at 100. Cheaper per mailbox does not mean more sending capacity, so compare Azure on cost per email sent, not cost per mailbox.

Azure annual pricing is not stated. InboxKit claims "better sender reputation from Azure IPs" but publishes no data for it. If you are weighing Azure against standard Microsoft 365 or Google, our guide to Google Workspace vs Microsoft 365 for cold email compares official limits and costs by mailbox type.

Domain costs: not published

InboxKit's standard domain registration price does not appear on its pricing page, homepage or knowledge base pages we read. The API quick start shows sample numbers in example responses, but they have no currency and are examples, so we do not cite them.

Here is what we can say:

Check the domain price in the app before you plan a large rollout. You can search domains inside InboxKit once you have a free account.

Add-ons and items without a published price

The Google Workspace knowledge base page also lists manual setup as "$6 + setup fees" in a comparison table. That is InboxKit's claim about doing it yourself, not an InboxKit price.

How you pay: wallet, cards and invoices

InboxKit runs on a wallet. You top it up by major credit card, and each mailbox charges on its own renewal date. Annual mailboxes are "Billed yearly from your wallet."

Agencies and enterprises can request volume invoicing on NET-30 terms. Signing up is free and needs no card, but the pricing page says "There is no traditional free trial on top of that." You pay only for the mailboxes you add.

Refunds, renewals and cancellation

InboxKit bills in advance, renews automatically, and says fees are generally non-refundable; domains are never refunded. You can cancel any mailbox from the dashboard before its renewal date, and the cancellation takes effect at the end of the period.

• "No pro-rata refunds are issued for unused time within a billing cycle."
• Quarterly and annual plans: cancelling early does not refund the remaining months.
• Mailbox renewals for Google Workspace, Microsoft 365 and SMTP are non-refundable once processed.
• Wallet top-ups are non-refundable, and the balance at closure is forfeited.
• Domains are never refunded, even if deliverability suffers.
• Warmup refunds are not addressed.

Discretionary exceptions (full or partial refund or credit):

• Duplicate billing.
• Paid services not provisioned and unresolved in a reasonable time.
• A platform-wide outage over 72 continuous hours (pro-rata).
• Termination by InboxKit without cause (pro-rata).
• Order delays over 48 hours (pro-rata credit for the delayed days only).

To ask, email finance@inboxkit.com with your account, invoice and a description. InboxKit says it responds within 5 business days and pays approved refunds in 7 to 10 business days. Contact billing before any chargeback: the terms say unauthorized chargebacks can lead to suspension and forfeited wallet credits.

The practical rule is to buy monthly until a setup proves itself, then move proven mailboxes to annual billing. Our full InboxKit review covers the terms and acceptable use policy that sit behind these rules.

InboxKit price vs resellers and competitors

The same InboxKit mailboxes are also sold inside Smartlead. Smartlead's SmartSenders marketplace lists "Google and Outlook Mailboxes by InboxKit" at $4.50 per mailbox a month plus $13 per domain a year, 1 to 5 mailboxes per domain, about 48 hours delivery, "exclusive to Smartlead and non-transferable." The article carries no date.

Prices are each vendor's list price as of November 2026, from their own pages (Zapmail, Cheapinboxes). Instantly requires an active Outbound plan to keep its done-for-you accounts and warmup running. Nerdy Joe is also an Icemail affiliate; our InboxKit vs Icemail comparison sets the two side by side.

Buying direct is cheaper per mailbox than buying InboxKit mailboxes through Smartlead. Buying through Smartlead gives you a published domain price and one bill with your sequencer. For more options, see our list of InboxKit alternatives.

Is InboxKit worth the price?

For Microsoft 365 and Azure mailboxes, InboxKit's price is among the lowest list prices in the category, with no minimum and DNS automation included. The real cost depends on three choices: billing cycle, warmup method, and domain count.

The cheapest sensible setup is usually monthly billing to start, warmup inside your existing sequencer, and three mailboxes per domain. Move to annual once mailboxes have run cleanly for a few months.

Two non-price points belong in the decision.

InboxKit's acceptable use policy says its Google Workspace mailboxes come under regional distribution arrangements for India and encourages customers outside India to consider Microsoft 365 or Azure. And its terms and policy require opted-in recipients. Both are covered in the InboxKit review.

When you are ready, price your setup in InboxKit's dashboard and start with a few domains.

Rather not build the list yourself?

Mailboxes are cheap; the list, copy, placement checks and reply handling are where the weekly hours go.

Nerdy Joe is owned by Agency Growth Partners (AGP), and AGP builds verified lists and runs outbound for agencies. If you would rather hand that off, book a call with David.

Disclosure: My relationship with Instantly is that of an independent party. I do not hold any position, nor do I have the power to form binding agreements or act on behalf of Instantly. My earnings are derived from referral compensations provided by Instantly. The views I share are solely mine and should not be seen as official statements, promises, or representations of Instantly, or any related entities or personnel.

Sources