Key takeaway
A free plan meters one of two things, the contacts you hold or the emails you send, and which one it picks decides whether it's generous for you. So the headline number tells you almost nothing on its own. A small list with a lot to send wants the contact meter; a big list mailed rarely wants the send meter. Different questions.
Start from what you already have. With a list and a newsletter, look at Sender, which meters 2,500 subscribers and hands you 15,000 sends a month against them. With an application sending from code, look at Brevo and Mailjet, where the meter is 300 emails a day. If an agent is running your email and you want the API switched on without paying, that's Nitrosend. I'd pick the meter first and the brand second.
The eleven worth signing up for.
1. Nitrosend
Unlimited contacts, 8,000 emails to start and then 500 a month, no daily cap, and no card. The MCP server, the REST API, and the CLI are all switched on for a free account, which is the thing every other free plan here gates, withholds, or hands over read-only.
Unlimited contacts changes something quieter than the number suggests. On a contact-priced free plan the list is the meter, so importing five thousand addresses you haven't mailed yet is what ends the free tier rather than any sending you did. Here the list costs nothing and only the sends count. Every capability is an endpoint and a tool before it's a screen, so the send test, the deliverability check, and the approval are reachable from the same command as the send, which is usually where an agent hands the job back to you.
Where it wins
- Unlimited contacts on every plan, including Free
- MCP, REST, and CLI cover the whole platform on the free tier
- No credit card, and no daily cap on the free allowance
- BYO sending keys on Pro and above cover Amazon SES, Resend, Postmark, Mailgun, and SendGrid
Where it runs out
- The monthly allowance after the first 8,000 is small next to Sender and EmailOctopus
- Email only, and sender-side only, so nothing here receives or parses inbound mail
- No product-feed sync with an ecommerce storefront
2. Sender
2,500 subscribers, 15,000 emails a month, no daily cap, one seat, and Sender branding on every send. Automation, landing pages, signup forms, and transactional email are all in the free plan rather than held back for a paid rung.
The detail worth knowing is how those two numbers relate. The bill is priced on subscribers and the send allowance is derived from it, at twelve times the subscriber count on Standard, so a small list mailed hard buys subscriber tiers it doesn't need. When the month's credits are gone, campaign sending stops until the cycle resets rather than metering an overage.
Where it wins
- 2,500 subscribers and 15,000 emails a month, with no card
- Automation, landing pages, and signup forms on the free plan
- Transactional email is part of the same product, not a second subscription
Where it runs out
- Sender branding stays on every free send
- One seat, so nobody else can work in the account
- Campaign sending stops when the month's credits run out
3. EmailOctopus
2,500 subscribers, 10,000 emails a month, no daily cap, one user, and EmailOctopus branding on every send, with reports kept for 30 days and a single landing page and form. No card to start.
Connect is the more interesting half, a separate free tier of its own: 2,500 subscribers with unlimited monthly sends routed through your own Amazon SES account, with AWS billing the volume. That makes the sending path yours rather than theirs. The limit is programmatic: the v2 API covers lists, contacts, fields, and read-only reporting, and has no endpoint that creates or sends a campaign.
Where it wins
- 2,500 subscribers and 10,000 emails a month, no card
- Connect routes sends through your own Amazon SES account
- Unsubscribed and bounced addresses drop out of the billed count
Where it runs out
- EmailOctopus branding on every free send
- No transactional product and no SMTP relay
- The API can't create or send a campaign
4. Systeme.io
2,000 contacts, unlimited emails, no daily cap, and limits that sit around the sending rather than on it: three sales funnels, one course, one custom domain, and one affiliate program.
Unlimited sending on a free plan is rare, and the catch is on the ladder above it, which is priced on contacts held: 2,000 free, 5,000 at $17 a month, 10,000 at $47, and unlimited contacts only at $97. The API and the official MCP server both write as well as read, but there's no transactional send in the documented surface, only newsletters and campaigns.
Where it wins
- Unlimited emails on the free plan
- 2,000 contacts before anything is billed
- An official MCP server that creates contacts, tags, and newsletters
Where it runs out
- Priced on contacts held, so a quiet list still moves the bill
- No transactional send in the documented API
- MCP keys expire after 90 days, two at a time
5. Zoho Campaigns
2,000 contacts, 6,000 emails a month, no daily cap, and five user seats, which is the outlier on a page where one seat is the norm.
The transactional half is a different product with a different bill. ZeptoMail is Zoho's SMTP relay and API, sold on credits, and its first credit is free at 10,000 emails valid for one month, so a free Zoho email stack is two accounts to set up. Before an agent is involved, check the other gap: neither Campaigns nor ZeptoMail is named on Zoho's published MCP app list, which covers the suite around the send rather than the send itself.
Where it wins
- Five user seats on the free plan
- 2,000 contacts and 6,000 emails a month, forever
- Contacts sync with Zoho CRM as one record
Where it runs out
- Marketing and transactional are two products on two bills
- Priced on contacts stored, so the bill grows with the list
- Campaigns isn't on Zoho's published MCP app list
6. Brevo
300 emails a day, forever, one user, and the Brevo logo on every send. The meter is the day rather than the month, which suits an application posting receipts steadily and works against a campaign that wants to leave all at once.
Transactional email is on the free plan, with an SMTP relay, a REST API, and outbound webhooks, and almost nothing else here offers that without paying. Read the cap before you build on it: 500 password resets in one afternoon fails against a 300-a-day ceiling. Removing the logo is what the $9 rung buys, and the MCP server is broad, covering 27 modules and writing rather than only reporting.
Where it wins
- Transactional sending on the free plan, with an SMTP relay and a REST API
- 300 emails a day with no monthly ceiling
- A broad MCP server covering 27 modules
Where it runs out
- The Brevo logo stays on every free send
- One user on the free plan
- A daily cap fails a burst that a monthly allowance would absorb
7. Mailjet
6,000 emails a month capped at 200 a day, 1,000 contacts, one user, and no automation, no A/B testing, and no segmentation on the free tier at all.
Do that arithmetic before you sign up. One campaign to the full 1,000 contacts takes five days to go out at 200 a day, and it can't be segmented when it does, so the free tier is a sending allowance rather than a marketing tool. What you get instead is where the mail sits and how an agent reaches it: EU data centres stated on the product page, and an official MCP server, Apache 2.0 licensed, which is read-only until a developer extends it.
Where it wins
- EU data centres stated on the product page
- An official MCP server, Apache 2.0 licensed
- MJML under the builder, so templates are portable as source
Where it runs out
- 200 emails a day, so one campaign to a full list takes days
- No automation, A/B testing, or segmentation on the free plan
- The MCP server is read-only by default
8. MailerLite
250 subscribers, 2,500 emails a month, no daily cap, and two seats, which is one more than most free plans here allow.
This is where the free plan and the paid product diverge most, and the divergence favours you on the way up: billing runs on active subscribers, people who unsubscribed or bounced drop out of the count, and the first rung is $12 a month for 500 subscribers, $49 at 5,000. The free plan itself is a dashboard, though. API and MCP access on Free doesn't include sending, which is a strange line to draw on a server that otherwise runs to roughly seventy tools.
Where it wins
- Unsubscribed and bounced addresses stop counting toward the bill
- Two seats on the free plan
- A broad official MCP server, roughly seventy tools
Where it runs out
- API and MCP access on Free excludes sending
- Transactional email is a separate product with its own bill
- 250 subscribers is a small ceiling to build a list on
9. Omnisend
250 contacts, 500 emails a month, no daily cap, 500 web push messages, and a Powered by Omnisend badge on every send. The free plan carries all core features rather than a cut-down subset.
Two things here are unusual on a free tier: unlimited user seats across six named roles, and 24/7 support. Watch what gets counted when you outgrow it. Billable contacts include non-subscribers who only ever received an order confirmation, so a store's order history becomes billable population without anybody opting into marketing, and the upgrade is charged prorated the moment a campaign would cross the limit.
Where it wins
- Unlimited user seats, including on the free plan
- 24/7 support on every plan
- An official MCP server with OAuth and role restrictions
Where it runs out
- The billed contact count includes non-subscribers who received an order confirmation
- 500 emails a month is a small allowance for a store
- No transactional single-send in the API
10. Mailchimp
250 contacts, 500 sends a month, capped at 250 a day, and sending that stops rather than meters when you reach either limit.
Two behaviours matter more than those numbers. Sending is paused when a free limit is hit, where a paid plan would take an overage charge instead, so what you notice first is a campaign that didn't go. Unsubscribed and non-subscribed contacts keep counting toward the limit too, and archiving them is the only way to stop paying for people who can't receive anything. The official MCP server covers Mailchimp Transactional rather than the Marketing API.
Where it wins
- An interface a non-technical marketer already knows
- A template library decades deep
- 300-plus integrations, included on the free plan
Where it runs out
- Unsubscribed contacts keep counting toward the 250-contact limit
- Sending is paused when a free limit is hit
- The official MCP server covers Transactional, not the Marketing API
11. Selzy
100 contacts, 1,000 emails a month, no daily cap, no expiry, and A/B testing, segmentation, and branding removal all sitting above the free line.
It's the smallest allowance here and one of the more complete ones. The builder, the automation, and the AI assistant are in the free tier rather than dangled above it, and the REST API is free on every account type including this one, covering lists, contacts, campaigns, templates, and sending. Paid plans price on contacts with unlimited sends, opening at $7.50 a month for 500 contacts.
Where it wins
- The REST API is free on every account type, including the free plan
- AI drafting and an email quality checker inside the editor
- Unlimited sends on every paid plan
Where it runs out
- 100 contacts is the smallest ceiling on this page
- A/B testing, segmentation, and branding removal are all above the free plan
- No first-party MCP server is published
What a free plan is actually metering.
A free email marketing plan is a permanent tier rather than a trial, and every one of them is priced on one of two things: the contacts you hold, or the emails you send. Most of these free tiers cap both, but only one of the two is the axis the price climbs on above the free rung.
Which means the headline number is usually the wrong number to shop on. A send-metered plan is roomy for somebody holding a big list and mailing it once a quarter. A contact-metered plan is roomy for somebody with almost no list and a lot to send.
Concretely: Sender sets its meter on the list, 2,500 subscribers, and hands you 15,000 sends a month to spend against it, which is room for a real newsletter without paying. Brevo counts the day, 300 emails of it, which fits an application posting receipts at a steady rate and breaks the moment a campaign wants to leave all at once. So the choice is which mistake you'd rather make. A contact-priced plan bills you for a list you aren't mailing; a send-priced plan bills you for mailing the list you have. I'd take the send meter almost every time, because a list is the asset you're supposed to be growing, and a meter that charges for growth ends up shaping the programme around the invoice.
What a free plan charges instead of money.
Every free tier on this page is an acquisition motion. The vendor is paying for your signup out of a marketing budget and expects to be repaid when you outgrow it. What's less obvious is that the eventual upgrade isn't the whole payment. A free plan takes something from you now, and across these eleven it takes the same four things.
- Branding: the vendor's logo or badge on every send, and on most of these the cheapest paid rung exists mainly to remove it.
- Seats: one user is the norm, which decides whether anybody else can touch the account.
- Withheld features: segmentation, A/B testing, send-time optimisation, and branding removal sit above the free line almost everywhere.
- Programmatic access: whether the API is switched on at all.
The fourth is the one to check first if anything other than a person is going to press send. MailerLite's free plan carries API and MCP access that doesn't include sending. Selzy's REST API is free on every account type, the free one included. Mailjet's official MCP server is read-only by default, so an agent can report on the account and not act on it. Read those together and the pattern is the cause, not the tier: agent access was added to products built for a human clicking buttons, so what an agent gets is the read paths the dashboard already had and not the send path.
What everything on this list had to clear.
Three conditions, and we set them deliberately low. The plan has to be permanent rather than a trial, so a fourteen-day window with a card on file at the end of it doesn't qualify however good the product is. Signing up has to work without a credit card, because a card is a commitment and not making one yet is the entire point of a free tier. And the limits have to be published where you can read them before you sign up, rather than discovered when a send fails.
A free plan isn't the same thing as a cheap plan, and two of the eleven are here because the upgrade is gentle rather than because the free tier is large. I'd shop the second rung harder than the first, because that's the one you actually pay. MailerLite at 250 subscribers and Selzy at 100 contacts are both small, and both open onto ladders that stay affordable for a long time after you leave the free rung.
The free plan isn't what decides whether the mail arrives.
Deliverability is a property of your domain and your list, not of your billing tier. The mailbox providers apply the same rules to a free account as to an enterprise one, and not one of those rules has a price attached to it.
They do have a volume threshold, and every capped allowance on this page sits well under it. Google treats a sender as bulk past 5,000 messages a day to Gmail accounts, per its sender guidelines, and the largest of those caps, 15,000 emails a month, averages 500 a day. Systeme.io is the exception, uncapped on sends and held down at the other end by 2,000 contacts. That isn't clearance. The requirements on the far side of that line are the ones worth adopting on day one anyway: SPF, DKIM, and DMARC on the sending domain, one-click unsubscribe on marketing mail, and a spam complaint rate under 0.30%, with 0.10% named as the level to actually run at. Yahoo asks for the same shape of thing in its own best practices, at a rate below 0.3%, and wants unsubscribes honoured within two days. That 0.30% ceiling is looser than it should feel: the automatic flag I used to run sat at 0.5%, five times over, and even then it was catching problems late rather than early.
No comparison table records whether a given free plan sets those headers correctly. One-click unsubscribe is a published standard, List-Unsubscribe and List-Unsubscribe-Post, defined in RFC 8058, and a platform either emits the pair on a campaign or it doesn't. Send yourself a real campaign on the free tier and read the raw headers.
Head to head, one at a time.
A shortlist card stops at the free plan. What it can't show you is the ladder above it: what the next rung costs at your list size, what a migration actually involves once contacts and automations have to move, and how much of the platform an agent reaches when you're paying.
- Nitrosend vs Sender
- Nitrosend vs EmailOctopus
- Nitrosend vs Systeme
- Nitrosend vs Zoho
- Nitrosend vs Brevo
- Nitrosend vs Mailjet
- Nitrosend vs MailerLite
- Nitrosend vs Omnisend
- Nitrosend vs Mailchimp
- Nitrosend vs Selzy
The vendors that aren't on this shortlist sit in the comparison index.
If the free plan you pick has to let a script send, start here. Nitrosend is an AI-native email platform, built sender-side to be driven by an agent rather than a dashboard with an API bolted on.
Nitrosend's free tier gives you 8,000 emails to begin with and then 500 a month, unlimited contacts, and the MCP server, the API, and the CLI all switched on with no card. The ongoing 500 a month is for proving one message type end to end through an agent, not for running a newsletter. Point one message type at it, let your agent run the checks as well as the send, and read the pricing ladder once you know what your real volume is.
Sources
- Google, Email sender guidelines: the 5,000-messages-a-day bulk threshold, the SPF, DKIM, and DMARC requirement, one-click unsubscribe, and the 0.30% and 0.10% spam rates.
- Yahoo Sender Hub, best practices: Yahoo's authentication requirements, the spam rate below 0.3%, and unsubscribes honoured within two days.
- RFC 8058: Signaling One-Click Functionality for List Email Headers, the standard behind the one-click unsubscribe header pair.
Common questions
Both exist, and the difference is worth settling before you sign up. Everything on this page is a permanent free plan with no credit card to start and published limits: Sender at 2,500 subscribers and 15,000 emails a month, Brevo at 300 emails a day, Nitrosend at 8,000 emails to start and then 500 a month with unlimited contacts. A 14-day or 30-day window that ends with a card on file is a trial, whatever the page calls it.
On the plans that meter the send, the range runs from about 500 emails a month to 15,000. Selzy gives 1,000 a month, Mailchimp and Omnisend 500, MailerLite 2,500, Zoho Campaigns 6,000, EmailOctopus 10,000, and Sender 15,000. Systeme.io sits outside that range with no monthly ceiling at all, against 2,000 contacts. Two plans meter the day instead of the month: Brevo at 300 a day and Mailjet at 200 a day inside a 6,000 monthly allowance, which matters because a daily cap fails a burst that a monthly allowance would absorb.
Systeme.io, on raw volume: its free plan carries unlimited emails against 2,000 contacts, which fits sending attached to a funnel or a course. For a real list, the answer is Sender, at 15,000 emails a month against up to 2,500 subscribers, with automation, landing pages, and transactional sending included. Both keep the vendor's branding on every send, which is the usual price of a large free allowance.
Most of them do. Brevo puts its logo on every free send and removing it is what the $9 rung buys. Sender, EmailOctopus, and Omnisend all brand the free tier as well, with Omnisend using a Powered by Omnisend badge. Where branding isn't the price, something else is: a small allowance, one seat, or a feature held above the free line.
Not reliably, and it's the thing to check first if a script or an agent is going to send. MailerLite's free plan includes API and MCP access that excludes sending. Mailjet's official MCP server is read-only by default. EmailOctopus has a documented API that can't create or send a campaign at all. Selzy's REST API is free on every account type, and Nitrosend puts the MCP server, the API, and the CLI on the free tier.
Yes, and the boundary usually isn't the send cap. It's the single seat, which stops anybody else working in the account, and the branding on every message, which is a real cost once you're selling something. Free plans also tend to withhold segmentation and A/B testing, so the programme you can run is broadcast rather than targeted. Plenty of businesses live there for a year.
Three different things, and they're worth knowing in advance. Mailchimp pauses sending when a free contact or send limit is reached, where a paid plan would take an overage charge. Sender stops campaign sends until the month's credits reset. Omnisend prompts an upgrade, charged prorated over the rest of the cycle, the moment a campaign would cross the contact limit. None of them is a surprise bill, and all of them are a campaign that doesn't go.
It depends on what the next rung counts, which is worth reading before you pick a free plan rather than after. Selzy opens at $7.50 a month for 500 contacts. MailerLite is $12 a month at 500 subscribers and $49 at 5,000, and it bills active subscribers, so unsubscribes and bounces drop out of the count. Brevo's $9 rung mostly buys the removal of its logo. Systeme.io prices on contacts held, $17 at 5,000 and $47 at 10,000, so a list you never mail still moves the bill.