Nitrosend vs Campaign Monitor.

Priced on sends, unlimited contacts, agent-native, with a published price at volume.

TL;DR

Campaign Monitor, now sold as Campaign Monitor by Marigold, is an email marketing platform built around campaign design, agency client accounts, and journeys. It's priced on the contacts you hold rather than the emails you send, and above its entry tier the sends are unlimited. If you mail a small, stable list often, that basis is the argument, and it's a real one. Where it runs out is agent control: automation built for humans clicking buttons lives behind screens, so an agent can read the account, not run it.

Nitrosend is an AI-native email platform that inverts the basis: contacts are unlimited on every plan including Free, the bill moves with the sends, and BYO sending keys on Pro and above keep the transport where you want it. Every capability is an API endpoint and an MCP tool before it's a screen, so the whole program answers to one agent command. Campaign Monitor charges you for the list. Nitrosend charges you for the mail.

The same contact-priced basis shows up across the category, so the Constant Contact comparison and the Dotdigital comparison are the neighbouring reads, while the Courier comparison covers the case where the sending is product notifications rather than campaigns.

Pricing math

What you actually pay.

The two ladders bill on different things. Campaign Monitor's rung is set by the contacts you hold, and its sends are unlimited from Essentials up; ours is set by the emails you send, and the contacts are unlimited. So the row to read is the one matching whichever of the two you have more of.

Scenario	Nitrosend	Campaign Monitor
Free	8,000 emails to start, then 500/mo forever. Unlimited contacts, 1 seat, full MCP, API, and CLI	No permanent free plan. A 30-day trial capped at 500 contacts and 500 emails
Entry paid tier	$20 Pro: 20,000 emails, 3 seats, BYO sending and AI keys	Lite from $13/mo at 500 contacts, sends capped near 5x contacts, so 2,500 emails. Essentials from $31/mo lifts the cap
10,000 contacts	$100 Ultra: 125,000 emails, 5 brands, 10 seats	Lite and Essentials both land between roughly $100 and $135 a month at this list size, and only Essentials lifts the send cap
50,000 contacts or more	$300 Enterprise: 500K to 4M+ emails at a published price, with SSO and SAML	Around $409/mo on Essentials, around $989/mo on Premier. Past 50,000 contacts it's a custom quote

Prices accurate as of August 2026. Check vendor sites for current rates.

Migration

How to switch (or run both).

Campaign Monitor keeps sending while you move, and its client accounts and any journeys you're mid-way through stay exactly where they are.

Add and verify your sending domain in Nitrosend. DKIM and SPF records sit alongside Campaign Monitor's, so both platforms can send from the same domain for as long as the overlap lasts.
Export each list from Campaign Monitor: open Lists and Subscribers, pick the list, use the three-dot menu, choose Export List, then pick the subscribers and the custom fields you want. Import that CSV with nitro_import_contacts, where the custom fields map onto custom fields.
Rebuild your templates rather than trying to move them. Nothing exports campaign HTML out of Campaign Monitor into another platform, so carry the design across and leave behind the modules nobody has edited in a year.
Start with one low-stakes message type, a receipt or a password reset, sent with nitro_send_message. Watch it for a week before a campaign follows it.
Rebuild journeys as flows with nitro_compose_flow, then decide what carries your reputation. BYO sending keys on Pro and above route mail through Amazon SES, Resend, Postmark, Mailgun, or SendGrid, and Campaign Monitor's own pool isn't one of them, so a sender leaving it is establishing a new sending path whichever platform it lands on. What travels with you is the domain and its authentication history.

Honest credit

What Campaign Monitor does well.

Picking a tool is about fit. Here's what Campaign Monitor is genuinely good at.

Unlimited email sends from Essentials up, so mailing daily costs the same as mailing monthly.
Agency client accounts: separate clients with their own lists, campaigns, and billing under one login.
Those client accounts are a Clients resource in the API rather than a workaround bolted on beside it.
A mature REST API at v3.3, covering subscribers, lists, campaigns, segments, templates, transactional, journeys to read and copy, clients, and webhooks.
Transactional email on the same account and the same API as campaigns, with access included from the entry paid tier.
Custom-coded HTML templates from that same entry tier, so a hand-built email is a first-class citizen rather than an upgrade.
Brand control for large teams on Premier: email section locking, template management, and advanced link tracking.
Send time optimization and advanced engagement segments on Premier.
A 15% nonprofit discount, published rather than negotiated.
Proactive deliverability monitoring and quarterly business reviews on the enterprise plan.

What Nitrosend adds

Where we think we're better.

Unlimited contacts on every plan, including Free, so a list that grows without being mailed never moves the bill.
The bill follows the sends, which is the basis you want when your list is much larger than your send volume.
A published price from 500,000 to over 4,000,000 emails a month, where this ladder ends in a custom quote.
A free plan that's a plan rather than a clock: 8,000 emails to start, then 500 a month, with the full MCP, API, and CLI on it.
MCP-first is an architecture, not an integration: every capability at Nitrosend is an API endpoint and an MCP tool before it's a screen.
Campaign Monitor's API reads journeys, summarizes them, and copies them, but publishes nothing that builds one.
Automation on Campaign Monitor stays something you assemble by hand in a dashboard, whatever is driving the rest of the account.
The difference shows at the edges: deliverability, billing, tests, and approvals are tools here, and those four are the ones that usually stop an automation dead.
BYO sending keys on Pro and above route your mail through Amazon SES, Resend, Postmark, Mailgun, or SendGrid, on your own domain and under a sending identity you own rather than a shared pool you can't take with you.
BYO keys are what make the move reversible: switching platforms otherwise means switching sending reputation on the same day, when the two failures look identical.

Use case fit

When to pick which.

Pick Campaign Monitor if

You mail a small, stable list very often, and unlimited sends above the entry tier make frequency free. It points the same way if you're an agency or a consultancy running many client accounts with their own lists and their own billing under one login, or if brand control across a large team is the requirement and locked sections inside a template are how you get it. None of those are close calls.

Pick Nitrosend if

Your list is much bigger than your send volume and you're tired of paying for addresses you don't mail. It's the right call too when you want a published price past the point this ladder turns into a sales call, or when you want the platform to answer to an agent end to end, including the billing, testing, and approval steps that usually send somebody back to a dashboard.

Campaign Monitor vs Nitrosend - common questions.

Can Nitrosend replace Campaign Monitor?

For the email program, yes. Campaigns, flows, segments, templates, contacts, and transactional sending are all here, and transactional isn't a separate product with a separate bill. The honest exception is agency work: if you run many client accounts with separate client billing under one login, that's a workflow to rebuild rather than a feature to switch on.

Is Nitrosend cheaper than Campaign Monitor?

It depends which of the two you have more of. At the entry rung Campaign Monitor's Lite starts from $13/mo at 500 contacts and our Pro is $20 for 20,000 emails. From there the ladders diverge: their bill rises with the contacts you hold and ours with the emails you send, so a big unmailed list is where the gap opens and a small list mailed daily is where it doesn't.

Does Campaign Monitor have a free plan?

No. The free option is a 30-day trial capped at 500 contacts and 500 emails, so an evaluation has a clock on it. Nitrosend's free plan is permanent: 8,000 emails to start, then 500 a month, unlimited contacts, and full MCP, API, and CLI access, with no card.

Can I move my subscribers without hurting deliverability?

The subscribers and their custom fields export from Campaign Monitor as CSV and import cleanly, so the shape of the list survives the trip. Reputation is the real question. Campaign Monitor sends from its own shared pool, which BYO sending keys don't cover, so the move is a new sending path either way and what carries across is the domain and its authentication history. Overlap on the same domain, and move one message type at a time.

Start with the free tier.

8,000 emails to start, then 500 a month, unlimited contacts, full MCP, API and CLI access. No credit card.