Key takeaway
A newsletter service holds your list, renders the campaign, and sends it on a schedule. The choice turns on the one thing a starting price never tells you, which is the number the bill counts. A newsletter is a list mailed over and over, so list size and send volume move independently, and every platform here prices on one of them and quietly caps the other.
Do that arithmetic before you shortlist anything. A weekly letter to 2,000 people is 8,000 sends a month and clears nearly every entry tier. The same letter sent daily is 60,000 sends and clears almost none, and on a contact-priced plan the only fix is buying subscriber tiers you don't need. I've watched more teams overpay on that gap than on any feature they compared.
The eleven worth looking at.
1. Nitrosend
Campaigns, flows, segments, templates, contacts, and transactional sending in one product, priced on sends rather than on list size. Free is 8,000 emails to start and then 500 a month, Pro is $20 for 20,000, Ultra $100 for 125,000, and Enterprise a published $300 from 500,000 to over 4 million.
The reason to pick it is the operating surface. Every capability is an API endpoint and an MCP tool before it's a screen, so an agent runs the deliverability check, the send test, and the approval as well as the send. BYO sending keys on Pro and above route the mail through Amazon SES, Resend, Postmark, Mailgun, or SendGrid.
Where it wins
- Unlimited contacts on every plan, including Free
- MCP, REST, and CLI cover the whole platform, not a read-only slice
- BYO sending keys keep an existing reputation on Pro and above
- A published price from 500,000 to 4M+ emails a month
Where it runs out
- Email only. No SMS, WhatsApp, push, or live chat
- Sender-side only, so nothing here receives or parses inbound mail
- No product-feed sync with an ecommerce storefront
2. MailerLite
The cheapest straight swap at the small end. Free covers 250 subscribers and 2,500 emails a month. Comfort is $12 a month at 500 subscribers, $49 at 5,000, $89 at 10,000, and $179 at 25,000. Power opens at $25 and lifts the send cap entirely under fair use.
What the subscriber headline doesn't say is that Comfort meters sending at ten times your tier ceiling, so a small list mailed hard hits a wall the price never mentions. Billing runs on active subscribers, and people who unsubscribed or bounced drop out. Transactional lives in MailerSend, with its own bill.
Where it wins
- Unsubscribed and bounced addresses stop counting toward the bill
- A website builder, landing pages, forms, and an email verifier in the subscription
- An official MCP server of roughly seventy tools that write as well as read
Where it runs out
- Transactional email is a second product with a second bill
- API and MCP sending need a paid plan
- The MCP tool list reaches no sending domain, deliverability, billing, or approval step
3. EmailOctopus
Simplicity sold cheaply, and the free tier is most of why it's here: 2,500 subscribers and 10,000 emails a month with no card, against EmailOctopus branding, 30-day reports, one landing page, one form, and one user. Pro opens at $9 a month at 500 subscribers, billed yearly.
Connect is the other half of the product, sending through your own Amazon SES account with AWS billing the volume directly. The quirk to know before you import is that each list bills independently, so the same person on two lists counts twice.
Where it wins
- A free tier a real sender can live on, with no card
- Connect keeps the send on your own Amazon SES account
- Automations branch on conditions, with tag, field, date, and API triggers
- A 20% lifetime discount for qualifying nonprofits
Where it runs out
- No transactional sending and no SMTP relay
- The API can't create or send a campaign
- No automation trigger on an open, a click, or an ecommerce event
4. Sender
Free Forever is 2,500 subscribers and 15,000 emails a month on one seat, and it includes automation, landing pages, forms, and transactional sending. Standard opens at $7 a month and Professional at $14, with monthly email credits at twelve times the subscriber count on Standard and twenty-four on Professional.
Campaign sending stops once the month's credits are used rather than metering an overage. And an active-subscriber count above the plan triggers an automatic upgrade before renewal, so list growth moves the bill without anyone deciding to.
Where it wins
- Transactional sending on the same product on every plan, including Free
- A REST endpoint and an SMTP relay, with signed webhooks for delivery, bounce, open, click, and complaint
- Landing pages, signup forms, and popups in the subscription
Where it runs out
- The free plan keeps Sender branding on every send
- Dedicated IPs are limited to Professional at 20,000 subscribers and above
- No first-party agent surface, so an agent arrives through a third-party connector
5. Brevo
A multichannel platform rather than a newsletter tool, and one of two here priced on emails sent. Free is 300 emails a day forever, one user, and the Brevo logo on every send. Starter is $9 a month from 5,000 emails, Standard $18, and Professional $499 from 150,000. Each is an entry price: the rate climbs with volume inside every plan.
Transactional is on every plan including the free one, with an SMTP relay, a REST API, webhooks, and unlimited log retention. The catch on Free is that the cap is per day, so 500 sends in one afternoon fails where a monthly allowance would absorb it.
Where it wins
- Transactional sending included from the free plan up
- An MCP server across 27 modules that writes as well as reads, contact import and export among them
- SMS, WhatsApp, push, and chat against the same contact record
Where it runs out
- The free plan brands every send and allows one user
- The published rungs jump from $18 to $499
- The MCP module list reaches no billing, approval, or send-test operation
6. Selzy
Contact-priced with unlimited sends on every paid plan, and the ladder is published a long way up. Free is 1,000 emails a month to 100 contacts with no expiry. Lite is $7.50 at 500 contacts, $30 at 5,000, $60 at 10,000, and runs to 500,000 at $1,100. Standard is $15 at 500 and $90 at 10,000.
None of that shows until you move the contact slider, and the page opens on the yearly tab with 30% applied, so the first number a visitor sees is the discounted one. Transactional at volume is UniOne, a separate product with its own account and bill.
Where it wins
- A published ladder that runs to 500,000 contacts on the entry plan
- Unlimited sends on every paid plan
- AI drafting and image generation at every tier, and a pre-send quality checker from the Standard plan up
- 24/7 support in six languages from the cheapest paid plan
Where it runs out
- Transactional at volume is a separate product with its own bill
- A dedicated IP is $20 to connect plus $40 a month on top of the plan
- Integrations are metered separately after 30 days
7. Loops
Built for SaaS teams who want product email, lifecycle flows, and the newsletter in one place. The free tier covers accounts under 1,000 contacts, capped at 4,000 emails in any rolling 30 days across marketing and transactional. Paid plans are tiered on contacts stored, and sends are unlimited on them.
The agent surface is unusually complete for a product this size: an MCP server, a CLI, a REST API, and installable Skills. What the MCP reaches is contacts, list membership, events that start workflows, and a published template.
Where it wins
- Unlimited sending on every paid plan
- An editor built on themes and reusable blocks, with MJML import
- Official Stripe and Segment integrations that trigger workflows from product events
Where it runs out
- Priced on contacts held, so the bill moves with list size
- No BYO sending keys, so an existing transport can't come with you
- The agent surface stops short of campaign creation
8. Flodesk
Templates that produce a polished email with no design work, priced on active subscribers with unlimited sends on every paid tier. Lite is one seat and one workflow and keeps the Flodesk footer, Pro adds a seat and one checkout, and Everything adds unlimited checkouts, sales pages, and subscriptions. Lite stops at 25,000 subscribers, the other two at 255,000.
The free plan can't send an email at all. It's forms, landing pages, link-in-bio, and segmentation, and it holds subscriber data until you upgrade. The flat unlimited plan closed to new signups on 1 December 2025, and a member already on it keeps that rate only while the subscription stays active.
Where it wins
- Templates that produce a polished email with no design work
- Unlimited sends on every paid tier
- Checkout sells digital products, services, and subscriptions from the same place as the list
Where it runs out
- The free tier sends nothing
- The API has no endpoint to compose, schedule, or send a campaign
- Split testing covers subject lines only
9. Mailchimp
The default most people already know, and onboarding a small team costs close to nothing. Free is under 250 contacts and 500 sends a month, and sending pauses at the limit. Essentials is $13 a month at 0 to 500 contacts, $75 at 2,501 to 5,000, and $110 at 5,001 to 10,000. Standard is $20, $100, and $135 across those same brackets.
The send allowance is a multiple of the contact ceiling rather than a number you buy: ten times on Essentials, twelve on Standard, fifteen on Premium. Subscribed, non-subscribed, and unsubscribed contacts all count toward the tier, so an address that can never be mailed again keeps billing until somebody archives it.
Where it wins
- A wide template library, and a UX most marketers already know
- 300+ integrations on every plan
- Send-time optimisation and generative drafting on Standard and Premium
Where it runs out
- Unsubscribed contacts keep counting toward the tier until they're archived
- Essentials caps an automation at four steps, so the entry plan can't run a lifecycle sequence
- The only official MCP server covers the transactional product, on a static account-level key
10. Constant Contact
Email and event marketing for small organisations, sold on human support rather than automation depth. There's no free plan: the entry route is a 14-day trial, and Lite, Standard, and Premium run at roughly $12, $35, and $80 a month at 500 contacts. Billing is on active contacts, and the send allowance is ten, twelve, and twenty-four times that count by plan.
Mail still goes out past the monthly allowance and bills at $0.002 an email, so this is one of the few here that meters an overage instead of stopping. The thing to time carefully is the exit, because cancelling runs through the support line.
Where it wins
- Phone support on every paid plan
- Event registration, ticketing, and guest lists inside the same product as the email promoting them
- Unsubscribed contacts move to inactive and stop billing
- Up to 30% off annually for nonprofits
Where it runs out
- Automation has no branching on a click and no conditional wait
- Lite is one user, one automation template, and one segment
- No transactional sending, so receipts need a second vendor
11. Campaign Monitor
An agency-shaped platform priced on contacts held. There's no permanent free plan, only a 30-day trial at 500 contacts and 500 emails. Lite caps sends at roughly five times the contact count, Essentials lifts the send limit entirely, and Premier adds phone support, send-time optimisation, engagement segments, and the website builder that is a $10 add-on below it.
Client accounts are the reason to pick it: a first-class concept in the product and a Clients resource in the v3.3 API, so an agency runs separate lists, campaigns, and billing under one login. Past 50,000 contacts the ladder ends and the next number is a quote.
Where it wins
- Unlimited sends from the middle tier up
- Separate client accounts with their own lists, campaigns, and billing under one login
- Custom-coded HTML templates from the entry paid tier
- Transactional sending on the same account and the same API
Where it runs out
- No permanent free plan, so an evaluation runs on a clock
- The entry tier caps sends at roughly five times contacts
- Journeys are read-only over the API, so nothing builds one programmatically
What a newsletter service has to do, and what this list leaves out.
A newsletter service holds a list, renders a campaign, and sends it on a schedule, and it's judged on whether the mail arrives and what the bill does as the list and the sending grow. Almost every page on this topic answers with a starting price at 500 subscribers, which is the one number that tells you nothing: a newsletter's cost is set by two variables and that figure holds only one of them still. I've watched a sender choose on it and hit a send ceiling twelve weeks later that no pricing page had mentioned.
Roundups on this topic usually mix in paid-subscription publishing products, where the platform hosts the archive, runs the paywall, and takes a cut of the revenue. That's a different job from sending to a list you already own. Everything above is a sending platform.
A platform decides what a newsletter costs to run and how reliably it lands. It doesn't decide what the newsletter is worth, and no shortlist can.
What the bill counts, and how it decides your shortlist.
Every platform above prices on either the size of your list or the volume you send, and almost none says which in the headline. The two bases, and the overlap:
| Platform | Send multiplier (x contact tier) |
|---|---|
| Mailchimp | 10x, 12x, or 15x, depending on plan. |
| MailerLite Comfort | 10x the subscriber tier. |
| Constant Contact | 10x, 12x, or 24x, and meters any overage instead at $0.002 an email. |
| Sender | 12x or 24x. |
| Campaign Monitor Lite | Around 5x. |
- Priced on the list: MailerLite, EmailOctopus, Sender, Selzy, Flodesk, Loops, Mailchimp, Constant Contact, and Campaign Monitor. Addresses you never mail still bill.
- Priced on the sending: Brevo and Nitrosend. The list can grow without the bill moving.
- Priced on the list and capped on the sending: a subset of the first group, not a class of its own, where the plan also meters sends at a multiple of the contact tier.
That overlap is where a newsletter gets caught, because a newsletter is the format that mails the same list over and over. Mailchimp allows ten, twelve, and fifteen times the contact ceiling by plan. MailerLite Comfort allows ten times the subscriber tier. Constant Contact runs ten, twelve, and twenty-four. Sender is twelve and twenty-four. Campaign Monitor Lite is around five.
Put a real schedule against those. A weekly letter to 2,000 people is 8,000 sends a month and clears all of them. A daily letter to the same 2,000 is 60,000 sends and clears almost none, and the only fix on a contact-priced plan is buying subscriber tiers you don't have. Constant Contact is the exception that meters an overage instead, at $0.002 an email.
There's a second-order effect worth knowing before you clean a list. On a platform that bills for unsubscribed addresses, hygiene costs you money for doing the thing that makes the rest of the mail land better. MailerLite and EmailOctopus drop unsubscribed and bounced people out of the billed count, and Constant Contact moves unsubscribes to inactive so they stop billing. Mailchimp keeps counting them until somebody archives them. the basis tells you which way the bill moves, not what it will be. Both bases look cheap at 500 subscribers, which is why every pricing page opens there.
Everything on this list clears the same floor.
The receiving side sets the rules and the platform only implements them. I've never seen a newsletter fail on the platform's rendering and I've seen plenty fail on these four. Four things a bulk sender has to get right, whichever name is on the invoice:
- Authenticate the domain: SPF and DKIM on the mail, plus a DMARC policy of at least
p=none, which Yahoo's sender best practices and Google both ask for. - Offer one-click unsubscribe: a
List-Unsubscribeheader carrying an HTTPS URI, paired with theList-Unsubscribe-Postheader RFC 8058 defines, alongside a visible link in the body. - Stay under the complaint threshold: below 0.30% at Gmail, with 0.10% as the level to actually run at, and below 0.3% at Yahoo.
- Know when the rules apply to you: Google's sender guidelines state them for anyone sending more than 5,000 messages a day to Gmail addresses.
All eleven platforms above authenticate the domain and add the header for you, so none of that separates them. What separates them is what happens when the number moves. A complaint rate creeping toward 0.30% is far easier to pull back early than late, and the difference is whether you saw it. So ask whether a platform hands back the complaint rate, the bounce split, and the domain reputation, and whether anything but a person in a browser can read them. The single biggest driver of that creep, in my experience, is frequency: complaint rates spike hardest when a list goes from getting almost nothing to three or four emails a week overnight, not when the volume is merely high.
None of it survives a list that was bought rather than built. No platform here fixes that, and the complaint rate it earns is charged against your domain, not theirs.
Which of them an agent can actually run.
An agent surface means the platform's own operations reachable as tools, not a connector wrapping the REST API somebody else published. Four of the other ten have one, and they reach different distances.
| Platform | MCP coverage | What's missing |
|---|---|---|
| MailerLite | Official, roughly seventy tools, writes as well as reads. | Sending domain, deliverability, billing, and approval. |
| Brevo | Official, 27 modules, including contact import and export. | Billing, approval, and send-test. |
| Loops | Official server, a CLI, and installable Skills. | Campaign creation. |
| Mailchimp | Official, transactional product only, static account-level key. | The entire marketing product. |
| EmailOctopus, Sender, Selzy, Flodesk, Constant Contact, Campaign Monitor | None first-party. | Everything; reached only through a third-party connector over the REST API. |
MailerLite publishes an official MCP server of roughly seventy tools that writes as well as reads, though nothing on it touches a sending domain, deliverability, billing, or an approval. Brevo's covers 27 modules including contact import and export, and names no billing, approval, or send-test module. Loops ships an MCP server, a CLI, and installable Skills, and stops short of campaign creation. Mailchimp's only official server covers the transactional product, on a static account-level key. EmailOctopus, Sender, Selzy, Flodesk, Constant Contact, and Campaign Monitor have no first-party surface, so an agent reaches them through a third-party connector over the REST API.
The pattern in where the coverage stops isn't an accident. Each of these products was designed for a person clicking buttons and the tools were added afterwards, so the operations that end a run, the send test and the approval and the bill, are the ones that never made it. An agent that can build the campaign and can't approve it hands the work back at the last step, which is the step you wanted it for. Nitrosend is the other shape, an AI-native email platform where the campaign, the send test, the approval, and the billing view are tools before they're screens. It specialises in the sending side, so reading an inbox or parsing a reply is somebody else's job.
Where each one gets compared properly.
Ten of the eleven have a full comparison against Nitrosend: the two pricing ladders side by side, the migration steps in order, and what that vendor genuinely does well.
- Nitrosend vs MailerLite
- Nitrosend vs EmailOctopus
- Nitrosend vs Sender
- Nitrosend vs Brevo
- Nitrosend vs Selzy
- Nitrosend vs Loops
- Nitrosend vs Flodesk
- Nitrosend vs Mailchimp
- Nitrosend vs Constant Contact
- Nitrosend vs Campaign Monitor
They all sit in the comparison index, alongside the vendors that didn't make this shortlist.
If what's pushing you off your current platform is a bill that moves with a list you aren't mailing, start on the free tier and send a real issue through it. Eight thousand emails to begin with, then 500 a month, unlimited contacts, and the MCP, API, and CLI all switched on with no card. Send one letter, watch the complaint and bounce numbers for a week, and read the pricing ladder once you know what your volume actually is.
Sources
- Google, Email sender guidelines: the 5,000-messages-a-day bulk-sender threshold, the SPF, DKIM, and DMARC requirement, one-click unsubscribe with a visible link, and the 0.30% and 0.10% spam rates.
- Yahoo Sender Hub, best practices: SPF and DKIM, a DMARC policy of at least p=none, a working one-click list-unsubscribe header, and a spam rate below 0.3%.
- RFC 8058: Signaling One-Click Functionality for List Email Headers, which defines the List-Unsubscribe-Post header and what the one-click POST has to carry.
Common questions
It depends which number the platform counts. On the contact-priced ones, 5,000 subscribers is roughly $30 a month on Selzy Lite, $49 on MailerLite Comfort, $75 on Mailchimp Essentials, and $100 on Mailchimp Standard, whatever you actually send. On a send-priced platform the subscriber count doesn't set the bill at all: Nitrosend is $20 for 20,000 emails a month with unlimited contacts, which covers a weekly letter to that list with room over.
Sender's is 2,500 subscribers and 15,000 emails a month, with automation and transactional sending included. EmailOctopus gives 2,500 subscribers and 10,000 emails, Brevo 300 emails a day, MailerLite 250 subscribers and 2,500 emails, Mailchimp 250 contacts and 500 sends, and Loops covers accounts under 1,000 contacts at 4,000 emails per rolling 30 days. Nitrosend's free tier is 8,000 emails to start and then 500 a month, with unlimited contacts. Flodesk's free plan sends nothing at all.
On MailerLite and EmailOctopus, no: unsubscribed and bounced addresses drop out of the billed count. Constant Contact moves unsubscribes to inactive, so they stop billing too. On Mailchimp, yes: subscribed, non-subscribed, and unsubscribed contacts all count toward the contact tier, and only cleaned, pending, and archived ones don't, so an address that can never be mailed again keeps billing until somebody archives it. On a platform priced on sends rather than contacts, the question doesn't arise.
Often not, because the send allowance on a contact-priced plan is a multiple of the contact tier rather than a number you buy. Mailchimp allows ten, twelve, and fifteen times the contact ceiling by plan, MailerLite Comfort ten times the subscriber tier, Constant Contact ten, twelve, and twenty-four, Sender twelve and twenty-four, and Campaign Monitor Lite around five. A daily letter to 2,000 people is 60,000 sends a month and clears almost none of those. Selzy, Flodesk, Loops, and Campaign Monitor above its entry tier sell unlimited sends instead.
SPF and DKIM on the sending domain, a DMARC policy of at least p=none, a one-click unsubscribe header pair with a visible link in the body, and a spam complaint rate under 0.30%, with 0.10% the level to actually run at. Google states those rules for anyone sending more than 5,000 messages a day to Gmail addresses. Yahoo asks for the same shape of thing and sets its own spam rate below 0.3%. Every platform on this page handles the authentication and the header for you.
It reaches the REST API through a third-party connector, so it can usually create a campaign, add or update contacts, and read a report, and anything the API doesn't publish stays out of reach. The connector is a second vendor to authorise, key, and pay for, and it can't invent an endpoint that doesn't exist, so the send test, the approval, and the billing view stay in the browser. On EmailOctopus, Sender, Selzy, Flodesk, Constant Contact, and Campaign Monitor that's the only route an agent has.
Part of it. The sending domain and its authentication history travel with you, and they're the larger half of how a mailbox provider judges you. The shared IP pool doesn't travel, because it belongs to the platform you're leaving, so the first move warms a new path whichever name you land on. What varies is whether it has to happen twice: BYO sending keys on Pro and above let the platform change without the transport changing again.
Not on all of them. Brevo, Sender, Campaign Monitor, Loops, and Nitrosend send transactional mail alongside campaigns. MailerLite splits it into a separate product, MailerSend, with its own bill. EmailOctopus, Flodesk, Constant Contact, and Mailchimp's marketing product don't send it at all, so receipts there mean a second vendor. Check the volume before you decide it doesn't matter, because transactional mail is usually the majority of what an application sends.