---
title: "InboxKit Pricing Breakdown (2026)"
description: "InboxKit pricing explained: one flat rate per mailbox from $2.50/mo on annual billing ($3.00 monthly). Full cost calculator and comparison with competitors."
canonical: "https://www.inboxkit.com/learn/inboxkit-pricing"
author: "Mohit Mimani"
published: "2026-03-30"
updated: "2026-03-30"
category: "Pricing"
---

# InboxKit Pricing: Complete Breakdown and Calculator (2026)

InboxKit charges one flat rate per mailbox with no plans and no included slots: $3.00/mo monthly, $2.70 quarterly, $2.50 annual. Warmup is a $3/mailbox/mo add-on and InfraGuard monitoring is included. Here is the complete cost breakdown.

## InboxKit Pricing Overview

InboxKit uses a **flat per-mailbox model**. There is one rate, it applies at every volume, and the billing cycle is the only discount:

| Billing Cycle | Per Mailbox | Minimum | 10 Mailboxes | 100 Mailboxes |
|---|---|---|---|---|
| **Monthly** | **$3.00** | none | $30/mo | $300/mo |
| **Quarterly** | **$2.70** | none | $27/mo | $270/mo |
| **Annual** | **$2.50** | none | $25/mo | $250/mo |

There is no base fee and no included-slot allowance, so your bill is simply mailboxes x rate. Mailboxes are charged from a prepaid wallet on each mailbox's own renewal date.

This is fundamentally different from competitors like Primeforge ($29/mo platform fee) or Instantly ($30-97/mo platform fee) that charge you before you even create a single mailbox.

## Core Pricing Breakdown

Here is the complete pricing table:

| Billing Cycle | Per Mailbox | Minimum | Saving vs Monthly |
|---|---|---|---|
| **Monthly** | **$3.00/mailbox/mo** | none | — |
| **Quarterly** | **$2.70/mailbox/mo** | none | **10%** |
| **Annual** | **$2.50/mailbox/mo** | none | **17%** |

| Add-On / Service | Price | Notes |
|---|---|---|
| Warmup | **$3.00/mailbox/mo** | Isolated warmup network |
| Azure Domain | **$30/domain** | Up to 100 mailboxes per domain |
| Domain Registration | From **$2/year** | DNS auto-configured |
| InfraGuard Monitoring | Per-domain pricing | Blacklists, DNS, reputation, auto-pause |
| Inbox Placement Tests | Per-test from wallet | Seed-based testing |

The rate covers both Google Workspace (US-IP) and Microsoft 365 mailboxes. Annual billing reduces costs further (e.g., Annual: $2.50/mailbox/mo/additional). As shown on the InboxKit pricing page (see screenshot above), everything is transparent. There are no hidden fees beyond the plan price, no overage charges, and no annual lock-in.

## Cost Calculator: Common Setups

| Setup | Mailboxes | Mailbox Cost (monthly) | Warmup ($3/ea) | Monthly Total |
|---|---|---|---|---|
| Starter | 10 | 10 x $3.00 = **$30** | $30 | **$60/mo** |
| Growth | 25 | 25 x $3.00 = **$75** | $75 | **$150/mo** |
| Scale | 50 | 50 x $3.00 = **$150** | $150 | **$300/mo** |
| Agency | 100 | 100 x $3.00 = **$300** | $300 | **$600/mo** |
| Large | 200 | 200 x $3.00 = **$600** | $600 | **$1,200/mo** |

On annual billing every mailbox figure above drops to $2.50, so 200 mailboxes is $500/mo rather than $600.

**Mixed provider example (200 mailboxes with warmup):**
- 200 mailboxes: 200 x $3.00 = **$600**
- Warmup: $3.00 x 200 = **$600.00**
- **Total: $1,200/mo** (before domains and InfraGuard)

Google Workspace and Microsoft 365 mailboxes are the same price. Domain registration, InfraGuard monitoring, and inbox placement tests are additional costs. DNS automation and 24+ sequencer integrations are included.

## InboxKit vs Competitor Pricing

**50 Mailbox cost comparison (monthly):**

| Provider | Plan / Pricing | 50 Mailbox Total | Notes |
|---|---|---|---|
| **InboxKit** | 50 x $3.00 flat (no plan fee) | **$150/mo** | Google + Microsoft, InfraGuard included |
| **ZapMail** | Growth $99/mo (30 incl.) + 20 x $3.25 | **$164/mo** | Google + Microsoft 365, no monitoring, no Azure |
| Maildoso | ~$2.50/mailbox flat | **~$125/mo** | Shared infrastructure |
| Primeforge | $3.50-4.50/mailbox | **$175-225+** | Varies by plan |
| Instantly | ~$4.00/mailbox + platform | **$230-297** | $30-97/mo platform fee |

ZapMail still sells plan tiers with included slots; InboxKit charges a flat per-mailbox rate with no plan fee, which is cheaper at volumes that fall between a competitor's tiers.

**What is included vs. extra:**

| Feature | InboxKit | ZapMail | Primeforge | Mailforge |
|---|---|---|---|---|
| Microsoft 365 | Yes | Yes | Yes | No |
| Azure Mailboxes | Yes ($30/tenant, 100 mailboxes) | No | No | No |
| Warmup | $3/mailbox/mo (isolated) | Pre-warmed option ($6-8/mailbox premium) | Warmforge $2/mailbox | Warmforge $2/mailbox |
| Monitoring | InfraGuard (per-domain) | None | Infraforge $1.50/mailbox | Infraforge $1.50/mailbox |
| Inbox Testing | Wallet-based | None | None | None |
| DNS Automation | Included | Semi-automated | Partial | None |
| Integrations | 24+ sequencers | 5 | 4 | 3 |

## Hidden Cost Comparison

Most competitors advertise a per-mailbox price but require additional paid services:

**ZapMail hidden costs:** Pre-warmed mailboxes at $6-8/mailbox premium, inbox testing (third-party $50-150/mo), monitoring (manual 4-5 hrs/week)

**Primeforge hidden costs:** Warmforge ($2/mailbox/mo), Infraforge ($1.50/mailbox/mo), inbox testing (third-party), monitoring (manual)

**Mailforge hidden costs:** Warmforge ($2/mailbox/mo), Infraforge ($1.50/mailbox/mo), SSL ($0.50/domain/mo), domain masking ($1/domain/mo)

**InboxKit additional costs:** Warmup at **$3.00/mailbox/mo** and InfraGuard at per-domain pricing are on top of your plan price. However, they are native to the platform. no third-party tools needed. DNS automation, inbox placement testing (wallet-based), and 24+ sequencer integrations are included in all plans.

## ROI Analysis

**The real question is cost per email delivered to inbox.**

With InboxKit at 100 mailboxes plus warmup:
- 100 mailboxes sending 40 emails/day = 4,000 emails/day
- 82% inbox rate = 3,280 inbox deliveries/day
- Mailboxes: 100 x $3.00 = **$300/mo**
- Monthly warmup cost: $3.00 x 100 = **$300**
- Total: **$600/mo** (before InfraGuard)
- Cost per inbox delivery: $600 / (3,280 x 30) = **$0.0061**

With a competitor at similar pricing but shared warmup and 75% inbox rate:
- Same volume: 3,000 inbox deliveries/day
- Monthly cost: ~**$500**
- Cost per inbox delivery: $500 / (3,000 x 30) = **$0.0056**

The per-delivery costs are in a similar range. InboxKit's advantage is the isolated warmup quality (which produces higher inbox placement) and InfraGuard monitoring (which catches issues before they tank deliverability). For teams where every percentage point of inbox placement matters, InboxKit's total value proposition is stronger.

## Getting Started

1. **Create your account** at inboxkit.com
2. **Choose a billing cycle** (monthly, quarterly or annual — the rate is $3.00, $2.70 or $2.50)
3. **Buy domains** and create as many mailboxes as you need
4. **Activate warmup** (**$3.00/mailbox/mo**) and InfraGuard (per-domain pricing)
5. **Start sending** after 14-21 days of warmup

No contracts, no plan fees and no minimum. Scale up or down anytime by adding or removing mailboxes.

## Frequently asked questions

### Does InboxKit have a monthly platform fee?

InboxKit charges one flat rate per mailbox — $3.00/mo monthly, $2.70 quarterly, $2.50 annual — with no plan fee and no included slots. There are no hidden platform fees. You pay for the mailboxes you create plus optional add-ons like warmup.

### What is the cheapest per-mailbox pricing on InboxKit?

There is no plan and no minimum — mailboxes are $3.00 each on monthly billing, so 100 mailboxes is $300/mo. On annual billing the rate drops to $2.50, making the same 100 mailboxes $250/mo.

### Is warmup included in InboxKit pricing?

No. Warmup is a separate add-on at $3.00/mailbox/mo on top of the mailbox rate. Warmup uses an isolated network for higher quality results compared to shared pools used by competitors.

### How does InboxKit compare to buying Google Workspace directly?

Google Workspace direct costs $7.20/month per user, and you handle DNS setup, warmup, and monitoring yourself. InboxKit is one flat rate per mailbox — $3.00/mo monthly, down to $2.50 on annual billing, with automated DNS and warmup available at $3/mailbox/mo as an add-on.

## Sources

- [InboxKit Pricing Page](https://www.inboxkit.com/pricing) (2026)
- [InboxKit Pricing Docs](https://www.inboxkit.com/#pricing) (2026)
- [Google Workspace Pricing](https://workspace.google.com/pricing) (2026)

## Related

- https://www.inboxkit.com/learn/what-is-inboxkit
- https://www.inboxkit.com/learn/inboxkit-review
- https://www.inboxkit.com/learn/zapmail-pricing