Pricing guide: prices as listed on vendor pages, checked 7 October 2026
AI-native email tools: pricing for inboxes and sending platforms
For a team that wants to send AI-assisted campaigns to a real list, Brevo is the best place to start in this guide. Its free plan allows up to 100,000 contacts and 300 sends a day at $0, and its Starter plan begins at $9 a month for 5,000 emails with no daily sending limit. For one person who wants an AI-assisted inbox rather than a sending tool, the answer is different. Superhuman, Shortwave, Spark and HEY do not publish a price on the pages checked for this guide, so they are compared on fit and marked "pricing on request".
Seven tools at a glance
The tools in this guide fall into two groups. The first four are inbox products that help one person read, sort and answer mail. The last three are sending platforms that email a list or a set of users, either on a schedule or in response to triggers. They solve different problems, so the table keeps them apart by category and shows the starting price with its plan and billing basis. Where a vendor does not publish a figure, the cell says so.
| Tool | Category | Best for | Starting price (plan, billing) | Key limitation |
|---|---|---|---|---|
| Brevo | Sending platform | Teams sending newsletters and automated emails to a contact list | Free plan at $0; Starter $9/month (monthly), from 5,000 emails | Free plan capped at 300 sends per day |
| Sender | Sending platform | Creators and small businesses with a modest subscriber base | Free Forever at $0; Standard $6.30/month, 6,000 emails and 500 subscribers | Free tier covers 2,500 subscribers; paid tiers list 500 subscribers |
| Customer.io | Behaviour-triggered messaging | Product teams messaging users from app events and profile data | Essentials $100/month (monthly billing) | Priced by profiles, so stored users raise the bill even with few sends |
| Superhuman | Personal inbox client | A single busy mailbox that needs fast handling | Pricing on request | A personal mail client, not a campaign platform |
| Shortwave | Personal inbox client | Gmail users who search and review long threads | Pricing on request | Designed around a single mailbox, not a list |
| Spark | Cross-platform mail app | Small teams that share an inbox across devices | Pricing on request | Team options depend on the plan, so the current list must be checked |
| HEY | Email service with its own addresses | People who want a screener for new senders and a separate mailbox | Pricing on request | A mailbox service, not a sending tool |
What "AI-native" means in this guide
The phrase is used loosely, so it helps to set a boundary. In this guide, an AI-native inbox tool is a mail client or mail service where AI features sit inside the core product: summarising threads, drafting replies, sorting incoming mail or searching by meaning rather than by exact keyword. A tool that has added a chat panel to an older interface does not qualify on that basis alone. Before relying on any AI feature, check on the vendor's own pages what it does and which plan includes it.
An AI-first sending platform is a different kind of product. It is a system for emailing a list or a set of users, and its AI features help write, segment or schedule that mail. Sending platforms are billed on a unit such as emails sent per month, subscribers or profiles stored, and that unit decides the real cost. An inbox client is usually billed per person. Putting the two on one price line is misleading, which is why the rest of this page keeps them in separate sections.
Prices in this category change often. Every figure below is taken from the vendor's own pricing page as it stood on 7 October 2026. Each table row names the plan, the billing view and the size the price applies to. Where a vendor does not publish a figure, the page says "pricing on request" and does not estimate one.
Superhuman
Superhuman is a personal email client. It suits a professional whose working day depends on one busy inbox and who wants to move through that mail quickly, with AI help inside the mailbox rather than in a separate tool. For that audience the question is simple: does the client shorten the time spent on mail that needs an answer today?
Where it falls short is scope. It manages your own mail. It is not a platform for sending newsletters, product messages or lifecycle emails to a list, so a team that wants to reach subscribers will still need a tool from the sending group in this guide.
Price: pricing on request. No figure is listed in this guide, so check the vendor for current plans and what each one includes before you commit.
Shortwave
Shortwave is an inbox client built around Gmail, with AI features aimed at search and at reviewing long threads. It suits a person who receives a steady flow of mail in Google accounts and needs to find a decision, a figure or an attachment from weeks earlier without scrolling through the whole history.
The limitation is the one that applies to any single-mailbox tool. It is built around one inbox, and it does not send bulk campaigns to a list. A team that needs to reach customers should pair it with a platform such as Brevo, Sender or Customer.io and keep the two jobs separate.
Price: pricing on request. No figure is given in this guide, so check the product's own pricing details for the current plan structure.
Spark
Spark is a cross-platform mail app with a smart inbox and shared-inbox features for small teams that answer the same address. Of the four inbox tools in this guide, it is the one oriented most directly toward a group working from a common mailbox, which makes it the natural first look for a small support or sales desk that already uses email as its front door.
Team sharing is the part to check most carefully. The options a team needs can depend on which plan it chooses, so confirm that a particular sharing feature is included before assuming it. The AI features matter less to this comparison than the team setup does.
Price: pricing on request. No figure is listed in this guide.
HEY
HEY is an email service with its own addresses, rather than a client layered on an existing account. Its screener lets a person decide once whether a new sender may reach them, and it separates bulk mail and receipts into their own views. People who want tight control over who can write to them tend to choose it for that reason.
It is not a sending tool and does not replace a platform for newsletters or product messages. Moving to a new address is also a bigger step than installing a client, so it suits a clean start better than a busy migration with many existing contacts and accounts.
Price: pricing on request. Check the vendor's own pricing information before you decide.
The sending platforms: Brevo, Sender and Customer.io
These three tools send email to people on a list or in response to behaviour. Their prices depend on how many emails, subscribers or profiles you use, so the same monthly budget can buy very different amounts of sending depending on the unit it is measured in.
Brevo
Brevo is a sending platform for newsletters, campaigns and automated messages. For a small team starting out, the free plan is the main attraction: it allows up to 300 email sends a day and stores up to 100,000 contacts. A team can run real campaigns before paying anything, provided each send fits within the daily cap.
The paid tiers step up by volume. Starter begins at 5,000 emails a month for $9 a month and removes the daily sending limit. Standard, at $18 a month for the same starting volume, adds automation, A/B testing and advanced reports. Professional is priced at $499 a month for 150,000 to 10 million emails a month and up to 2 million contacts. The yearly toggle on the vendor page shows $449.08 with a 10% reduction on that plan.
Where it falls short: the free plan's daily cap means a large campaign may need to run over several days, and a team that relies on automation will need Standard or higher. The plan details are the place to confirm what each tier includes before you choose.
Price: free; Starter $9/month; Standard $18/month; Professional $499/month. Brevo pricing page.
Sender
Sender is a low-cost sending platform aimed at creators and small businesses. Its free plan, Free Forever, covers 2,500 subscribers and 15,000 emails a month at no charge. That makes it one of the least expensive ways to start a newsletter with a small audience, and it suits a writer who wants to test a regular send schedule before spending money.
The two paid tiers are Standard at $6.30 a month, which covers 6,000 emails and 500 subscribers, and Professional at $10.50 a month, which covers 12,000 emails and 500 subscribers. The vendor shows the same monthly figure for annual billing on both. Because each paid tier lists 500 subscribers, a list larger than that must be checked against the current plan details before a tier is chosen.
Where it falls short: the paid tiers are sized for small audiences. A team with a bigger list should not assume the lower tiers will hold it, and should confirm the subscriber limits on the pricing page before committing.
Price: free; Standard $6.30/month; Professional $10.50/month. Sender pricing page.
Customer.io
Customer.io sends messages triggered by what people do in a product, such as signing up, changing a plan or leaving a step unfinished. It suits product teams that want messages tied to app events and profile attributes rather than to a fixed send calendar. The Essentials plan includes AI Agent core skills, a visual workflow builder, email and community support, and basic data integrations.
Pricing is set by profiles and by the plan. Essentials starts at $100 a month with monthly billing. The profile-based Essentials tiers are $145 a month for 10,000 profiles, $235 for 20,000, $325 for 30,000, $415 for 40,000, and $505 and up for 50,000 profiles and above. Premium is priced at $1,000 a month with custom profile volume, elevated AI Agent limits and premium support.
Where it falls short: a large profile count raises the bill even when the number of messages is modest, so a list that is rarely emailed still costs money while its profiles are stored. Eligible early-stage companies that have raised under $10 million can receive 12 months free through the Startup Program, so check that eligibility before you pay for a tier.
Price: Essentials $100/month; profile tiers from $145/month for 10,000 profiles; Premium $1,000/month. Customer.io pricing page.
Published monthly prices at real list sizes
The table lists each sending plan at the size it covers. Figures are monthly prices as shown on the vendor pages, and each row names the billing view. Where a plan has no price for a given size, the row says so instead of filling the gap with an estimate. The inbox tools are included with "pricing on request" because no price is published for them on the pages checked for this guide.
| Plan | Size it covers | Monthly price | Billing view | What to note |
|---|---|---|---|---|
| Sender Free Forever | 2,500 subscribers, 15,000 emails/month | $0 | Free | Fits a small list only |
| Sender Standard | 6,000 emails/month, 500 subscribers | $6.30 | Monthly figure as listed | Same figure shown for annual billing |
| Sender Professional | 12,000 emails/month, 500 subscribers | $10.50 | Monthly figure as listed | Same figure shown for annual billing |
| Brevo Free | Up to 100,000 contacts, 300 sends/day | $0 | Free | Daily cap applies |
| Brevo Starter | From 5,000 emails/month | $9 | Monthly | No daily sending limit |
| Brevo Standard | From 5,000 emails/month | $18 | Monthly | Adds automation, A/B testing and advanced reports |
| Brevo Professional | 150,000 to 10 million emails/month, up to 2 million contacts | $499 | Monthly (yearly toggle shows $449.08) | Yearly toggle shows a 10% reduction |
| Customer.io Essentials | Base plan with AI Agent core skills | $100 | Monthly | Monthly billing as listed |
| Customer.io Essentials 10k | 10,000 profiles | $145 | Monthly | Billed monthly |
| Customer.io Essentials 20k | 20,000 profiles | $235 | Monthly | Billed monthly |
| Customer.io Essentials 30k | 30,000 profiles | $325 | Monthly | Billed monthly |
| Customer.io Essentials 40k | 40,000 profiles | $415 | Monthly | Billed monthly |
| Customer.io Essentials 50k+ | 50,000 profiles and above | $505+ | Monthly | Shown as $505+ on the vendor page |
| Customer.io Premium | Custom profile volume | $1,000 | Monthly | Higher AI Agent limits and premium support |
| Superhuman, Shortwave, Spark, HEY | One personal or team mailbox | Pricing on request | Not published on the pages checked | Check the vendor for current plans |
Worked costs for three buyers
A newsletter writer with a small list. Sender's Free Forever plan covers 2,500 subscribers and 15,000 emails a month at $0. If the list grows past that, Standard at $6.30 a month is the next listed step. It covers 6,000 emails and 500 subscribers, so both the subscriber count and the monthly send volume must fit before the tier is chosen. Over twelve months, Standard would cost 12 × $6.30 = $75.60.
A small company sending campaigns and automations. Brevo's Starter plan at $9 a month covers from 5,000 emails and removes the daily limit. Moving to Standard at $18 a month costs 12 × $18 = $216 over a year and adds the automation and A/B testing that a campaign team usually needs. Before buying, check whether the free plan's 300-sends-a-day cap is enough for the first campaigns. If it is not, Starter is the lowest listed price that lifts it.
A product team messaging 20,000 users. Customer.io's Essentials 20k tier is $235 a month, which comes to 12 × $235 = $2,820 over twelve months. That figure is priced on profiles, not sends, so it measures a different unit from Brevo's and Sender's prices. Compare the options using the unit your business actually tracks: profiles stored or emails sent. Setting $235 for 20,000 profiles against $9 for 5,000 emails tells you nothing useful on its own.
Which tool fits which need
The decision depends on the job. A single inbox and a contact list are different problems, and the table matches each common need to the category that handles it, with the reason and the price where one is listed.
| If you need | Pick | Because |
|---|---|---|
| A free way to send campaigns to up to 100,000 contacts | Brevo Free | The free plan covers that contact count at 300 sends a day; move to Starter from $9/month when daily volume grows |
| A $0 start for a small subscriber base | Sender Free Forever | It covers 2,500 subscribers and 15,000 emails a month at no charge |
| Messages triggered by app events and profile changes | Customer.io | It is built around profiles and events; Essentials starts at $100/month on monthly billing |
| An AI assistant for one Gmail or other personal inbox | Superhuman or Shortwave | Both are personal clients; pricing is on request, so compare current terms with the vendor |
| A shared inbox for a small team across devices | Spark | Its shared-inbox features are the main reason to choose it; confirm which options your plan includes |
| A mailbox with its own address and a screener for new senders | HEY | It is a full email service rather than a client, and its screener handles new senders |
How to choose
Start by separating the two jobs. If you need to read, answer and organise your own mail faster, look at the inbox group. If you need to reach a list or a set of users, look at the sending group. Many people need both, and in that case the two do not compete: a personal client for your own inbox, and a sending platform for the audience.
Next, pick the billing unit that matches how your business grows. A platform priced by emails suits a newsletter that goes out often to a modest list. A platform priced by profiles suits a product where many users are stored but only some receive messages at any moment. Model your next twelve months in that unit before comparing prices, because the cheapest starting plan is not always the cheapest plan a year later.
Then check the limits that could block you. The free plan of a sending tool may cap daily volume, and the lower paid tiers may cap subscribers. An inbox client may be built around one account type, and a team tool may reserve sharing features for a particular plan. Each of these limits is easy to find on the vendor's pricing or feature page and easy to miss if you read only the headline price.
Finally, consider the people on the other end. An AI feature that drafts a campaign is only useful if a person checks the result before it reaches a list, and an AI inbox that summarises threads is only useful if you still read the messages that carry real obligations. Choose the tool that keeps a human in the loop for the work that matters.
Setup and migration checklist
Moving a list or a set of automations to a new sending tool takes more care than moving a mailbox. The steps below apply to Brevo, Sender and Customer.io alike, and each one protects either deliverability or the people on your list. For the inbox tools, the last row is the main step.
| Step | What to check | Why it matters |
|---|---|---|
| 1. Export contacts and suppression lists | Carry over unsubscribes and bounced addresses from the old tool | Prevents mailing people who have already opted out |
| 2. Authenticate the sending domain | Set up SPF, DKIM and DMARC records for your domain | A new platform needs this in place before any bulk send |
| 3. Define profile attributes (Customer.io) | Decide which attributes trigger messages and which can be left out | The profile count drives the monthly bill |
| 4. Check the daily send cap (Brevo Free) | Compare the planned send size with 300 sends per day | Large campaigns may need to be split across several days |
| 5. Check the subscriber count (Sender) | Compare the list size with the 2,500-subscriber free limit and the 500-subscriber paid figure | Shows which tier the list actually needs |
| 6. Review AI-written copy by hand | Send to a small segment first and check every claim before a wider send | Keeps the voice consistent and avoids unsupported statements |
| 7. Connect one inbox account first (inbox clients) | Review the permissions the app asks for before connecting more accounts | Limits access while you see how it handles your mail |
Keep the old platform running until the first two campaigns on the new one have gone out cleanly. Compare open and bounce figures across both during that period, and remove a contact from the old list only after the new list has been checked against it.
Related
- Top 15 AI-native email tools: the full list with categories and use cases.
- Pricing overview: the main pricing comparisons side by side.
- Customer.io pricing guide: when profile-based pricing makes sense.
- Brevo pricing guide: the free plan and the paid tiers in detail.
Frequently asked questions
Which tool should a small team start with?
For a team that needs to send campaigns to a list, Brevo's free plan is the easiest place to begin. It covers up to 100,000 contacts with 300 sends a day at $0. When daily volume grows, Starter begins at $9 a month for 5,000 emails and removes the daily sending limit.
Can an AI inbox client send newsletters?
Personal inbox clients such as Superhuman, Shortwave and Spark are designed to manage one person's mail or a small shared inbox. They are not built for sending campaigns to a list. Use a sending platform from the second group for newsletters and automated messages.
Why is no price listed for Superhuman, Shortwave, Spark or HEY?
This guide shows a price only where the vendor publishes one on the pages checked for it. For these four tools no figure was published there, so the tables say pricing on request. Ask the vendor for its current plans and what each one includes before you decide.
Why can Customer.io cost more for a large list that is rarely emailed?
Customer.io prices by profiles as well as by plan. Each stored profile counts toward the tier you need, so a large list that receives few messages can still move you into a higher tier. Count how many profiles you need to keep active before choosing a plan.
What are the limits on Brevo's free plan?
The free plan allows up to 300 email sends a day and stores up to 100,000 contacts. The daily cap is the limit most likely to affect a campaign, so plan larger sends across several days or move to a paid plan.
Does Sender's free plan have a subscriber limit?
Yes. Free Forever covers 2,500 subscribers and 15,000 emails a month. A list above that needs a paid plan, and the paid tiers in this guide list 500 subscribers, so compare the current plan details before choosing.
Is Customer.io's startup offer available to everyone?
No. The Startup Program is for eligible early-stage companies that have raised under $10 million, and those companies can receive 12 months free. Check the eligibility terms on the pricing page before you apply.