Key takeaway
A drip campaign is a series of emails that fires off a trigger and runs to a schedule, and every platform on this page builds one. So the builder isn't what separates them. What separates them is what the bill is counted on, and whether anything other than a person in a browser can drive the sequence once it's live.
Some meter emails sent, most meter contacts held, and one meters anyone with a recent event, so the same monthly figure buys a different thing on each. Klaviyo if the sequence has to know what someone bought, Encharge if the trigger is a product event, MailerLite if the list is small, and Nitrosend if email is the channel the programme runs on. In my experience sequences die against Gmail's 0.30% complaint ceiling, not in the builder.
The twelve worth looking at.
1. Nitrosend
Campaigns, flows, segments, templates, contacts, and transactional sending in one product, priced on what you send rather than on list size. Free is 8,000 emails to start and then 500 a month, Pro $20 for 20,000, Ultra $100 for 125,000, and Enterprise a published $300 up to over 4 million.
Contacts are unlimited on every plan, including Free, which matters on a drip programme: a welcome sequence collects addresses faster than it burns send volume. Nitrosend is MCP-first, so every capability is an API endpoint and an MCP tool before it's a screen, and BYO sending keys on Pro and above route 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 your existing reputation on Pro and above
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. ActiveCampaign
The visual automation builder is why people shortlist it: multi-branch flows with waits, conditions, and scoring are easy to draw. There's no free plan, only a trial. At 1,000 email contacts billed annually it's $15 a month on Starter, $49 on Plus, and $79 on Pro; at 10,000 those become $149, $189, and $375.
Two things bite on a drip programme. Starter caps an automation at five actions, so unlimited actions begin one plan above the headline price, and the enhanced CRM most buyers come for, with pipelines and lead scoring, is an add-on rather than part of the plan.
Where it wins
- Strong visual builder with waits, conditions, and scoring
- A CRM layer on all four plans, alongside 1,000+ integrations
- Claude and ChatGPT access over MCP is a listed platform integration
Where it runs out
- No permanent free plan, only a 14-day trial
- Every published price is billed annually, with no monthly rate stated
3. Encharge
Marketing automation for B2B SaaS, where a flow fires on what somebody did inside your application rather than on what they clicked. Native Stripe, Chargebee, Recurly, Chargify, and Paddle integrations push trial, payment, and churn events straight into a sequence. Growth is $99 a month at 2,000 subscribers and Premium $159, rising to $550 and $879 at 49,000.
The meter is subscribers held, and the send allowance derives from it: ten times the limit on Growth, twelve on Premium, then $100 for every 100,000 emails over. A transactional send to an address Encharge doesn't already hold creates a billable person, and so does an anonymous visitor who entered a flow.
Where it wins
- Behaviour emails built on product events rather than on clicks
- Free email verification for every contact, on all plans
- Unlimited team members and unlimited flows on both paid plans
Where it runs out
- No free plan, only a 14-day trial
- Sends capped at a multiple of the subscriber limit, then billed as overage
- No first-party agent surface in the published developer documentation
4. Klaviyo
The ecommerce marketing CRM the category defaults to, and on a store with a large list it earns that: catalog analysis, predictive analytics, and revenue attributed back to the flow. The email line runs $20 at 500 active profiles, $150 at 10,000, and $1,955 at 150,000, the last stop carrying a price.
The included allowance is ten times the active profile count at every stop, so volume and list size move together whether your programme does or not. An active profile is anyone Klaviyo could email, consent aside, so an unengaged list costs what an engaged one does until it's suppressed. The steepest stretch runs from $150 to $325 between 10,000 and 13,500 profiles.
Where it wins
- 350+ pre-built integrations, with predictive analytics included
- A broad MCP server covering campaigns, flows, segments, and reporting
- Suppressed profiles stop counting toward the billable total
Where it runs out
- Built around a store, so a SaaS sender pays for a layer it can't use
- No bring-your-own sending keys, so reputation can't be carried across
- Crossing the profile limit moves the plan up at the next billing cycle
5. Brevo
A multichannel platform rather than an email tool: email, SMS, WhatsApp, push, live chat, and a small sales CRM against one contact record. Free is 300 emails a day with the Brevo logo on every send. Starter is $9 a month from 5,000 emails, Standard $18, and Professional $499 from 150,000 emails.
It's metered on emails sent rather than contacts held, the kinder model for a drip programme whose list grows faster than its volume. Two catches. The free cap is daily, so 500 messages in one afternoon fails where a monthly allowance absorbs them, and the published rungs jump straight from $18 to $499.
Where it wins
- Priced on sends, so the list can grow without the bill moving
- Transactional email on every plan, including Free
- A broad MCP server across 27 modules, writing as well as reading
Where it runs out
- The free plan brands every send and allows one user
- The free cap is daily, so a burst fails where a monthly one wouldn't
6. Mailchimp
The default most people already know, with a template library decades deep and an interface your next hire needs no training on. Free is 250 contacts and 500 sends a month. Essentials opens at $13 a month at 500 contacts and Standard at $20, with Standard at $135 for 5,001 to 10,000 contacts.
Unsubscribed contacts keep counting toward the tier, and archiving is the only way to stop paying for one. The send allowance is a multiple of the contact limit rather than a number you choose: ten times on Essentials, twelve on Standard. Essentials also caps automation at four flow steps, so a real drip programme starts at Standard.
Where it wins
- A template library decades deep, and an interface most marketers know
- 300+ integrations, included on every plan
- Send-time optimisation and pre-built templates from Standard up
Where it runs out
- The entry plan caps automation at four flow steps
- The only official agent server covers the transactional product
7. MailerLite
Low-cost email marketing for small senders, with a website builder, landing pages, forms, and an email verifier in one subscription. Free covers 250 subscribers and 2,500 emails a month. Comfort is $12 a month at 500 subscribers, $49 at 5,000, and $179 at 25,000; Power starts at $25 and lifts the send cap.
The detail worth knowing is what they count. Billing is on active subscribers, and people who unsubscribed or bounced drop out of the number, the opposite of most contact-priced platforms. Comfort still meters sends at ten times your tier ceiling. Transactional isn't part of it: that's MailerSend, with its own bill.
Where it wins
- Unsubscribed and bounced addresses stop counting toward the bill
- An MCP server of roughly seventy tools, including automation dry runs
- A website and landing-page builder in the same subscription
Where it runs out
- API and MCP sending both need a paid plan
- Transactional email is a separate product with a separate bill
8. Loops
Marketing, product, and transactional email in one opinionated product, with a design-led editor, workflows carrying branching and experiments, and goals tracking conversions. Free is open under 1,000 contacts and capped at 4,000 emails in any rolling 30 days. Paid plans are tiered by contact count with no published ladder, only a slider on the pricing page.
Sends are unlimited on every paid plan, so the meter is contacts stored and a sequence growing from four emails to nine costs nothing extra. The agent surface is unusually complete for a product this size: a CLI, a REST API, an MCP server, and installable skills. That MCP is contact and send shaped, and doesn't reach campaign creation.
Where it wins
- Unlimited sends on every paid plan
- A CLI, an MCP server, and installable agent skills alongside the API
- Official Stripe and Segment integrations among 22 named partners
Where it runs out
- Priced on contacts stored, so a quiet list still moves the bill
- No bring-your-own sending keys
9. Drip
One plan, no feature tiers, and a price that moves only with list size, which makes it the simplest thing here to budget. Automation, segmentation, and reporting are on from the first paid rung, and seats are unlimited. It opens at $39 a month for 2,500 active people and $89 at 5,000.
The meter is active people, and unsubscribed people stay inside that count, so a list you can no longer mail keeps its place on the bill. The charge for a cycle is set by the highest number the account held at any point in it, so one spike prices the month.
Where it wins
- One plan with no feature gating between rungs
- Unlimited user seats, with onsite popups and forms in the product
- A documented REST API with published rate limits and client libraries
Where it runs out
- No free plan, and the trial is capped at 100 total sends
- No first-party agent server, so an agent goes through someone else's wrapper
10. Omnisend
An ecommerce platform selling email, SMS, and web push against one contact record, with native storefront integrations as the route in. Free is 250 contacts and 500 emails a month. Standard is $16 a month from 500 contacts and Pro $59 from 2,500 with unlimited emails.
Billable contacts include non-subscribers who only ever received an automated order confirmation, so a store's order history becomes billable population without anybody opting into marketing. Standard meters email credits at twelve per contact per cycle, so mailing the same list more often needs a bigger list.
Where it wins
- Unlimited user seats on every plan, across six named roles
- 24/7 support on every plan, including Free
- A four-tool MCP server that reaches the whole API rather than a fixed list
Where it runs out
- The entry plan ties send volume to list size at twelve per contact
- No transactional single-send route in the documented API
11. GetResponse
An all-in-one platform with landing pages, a website builder, webinars, and a course creator in the same product as the list, and sends are unlimited on every paid plan. Free covers 500 contacts and 2,500 newsletters a month. Starter is $19 a month at 1,000 contacts, Marketer $59, and Creator $69; at 10,000 they're $79, $114, and $134.
Billing is on the peak active subscriber count during the month plus every contact added within it, so an import you reversed the same afternoon still prices the whole cycle. Starter allows one custom automation workflow, so a real drip programme starts at Marketer.
Where it wins
- Unlimited sends on every paid plan, so cadence never moves the bill
- Three users on the entry plan and five above it
- A permanent free plan with no time limit and no card
Where it runs out
- The entry plan allows one custom automation workflow
- No first-party agent server, and transactional is a quoted add-on
12. Bento
An email platform whose differentiator is the AI surface rather than the template library, sold as three separately purchased products. Marketing is $29 a month to 5,000 Active Users with unlimited sends and seats included, then $0.01 per Active User to 50,000 and $0.009 to 250,000. Transactional is billed separately at $5 a month.
An Active User is anyone subscribed or carrying an event in the last thirty days, so a site running their tracking script can hold billable records nobody ever mailed. Nothing sends until a human has approved the account, and approval asks for a website, a privacy policy, list provenance, and engagement history.
Where it wins
- A published price at every size, with no quote-only rung
- Unlimited marketing sends and team seats on every paid plan
- A hosted MCP endpoint where a new broadcast always lands as a draft
Where it runs out
- No free plan on the marketing side, only a 30-day trial
- Marketing, transactional, and chat are three separate line items
What every tool on this list had to clear.
Four requirements, and every platform above meets all four. A shortlist is worth nothing if the floor under it stays unstated, so here's the one this page used. I've watched teams pick a drip tool off a branching screenshot and then find the bill runs on contacts they never mail, which is why the meter is on this list and the canvas isn't.
- Real branching: a trigger and a condition, not a timed autoresponder chain.
- A published price: a number a buyer can read before talking to anybody.
- A way out: contacts and their custom fields export without a support ticket.
- A programmable surface: an API at minimum, so the sequence isn't trapped in a browser tab.
That floor removed the cold-outreach tools, which send sequences but branch on almost nothing, and the CRM suites, which clear all four and then price the email half as a line item on a much bigger bill. It also removed anything you can only get a price for by booking a call, because the cost of a drip programme depends on how fast the list and the volume grow, and you can't model that against a quote.
Compare the meter, not the headline price.
A starting price is the number at the smallest bracket of the cheapest plan, and on its own it tells you very little: the same monthly figure buys a different thing depending on what the platform counts.
| Platform | Meter type | What actually gets counted |
|---|---|---|
| Mailchimp | Contacts held | Bills unsubscribed contacts along with active ones. |
| ActiveCampaign | Contacts held | Tracks list size, so mailing more or less often doesn't move the bill. |
| Klaviyo | Contacts held | Tracks list size, so mailing more or less often doesn't move the bill. |
| MailerLite | Contacts held | Drops unsubscribed and bounced addresses out of the count entirely. |
| GetResponse | Contacts held | Adds everyone who joined during a month, whether or not they were still on the list at the end of it. |
| Loops | Contacts held | Tracks list size, so mailing more or less often doesn't move the bill. |
| Encharge | Contacts held | Tracks list size, so mailing more or less often doesn't move the bill. |
| Omnisend | Contacts held | Counts non-subscribers who only ever received an order confirmation. |
| Drip | Contacts held | Bills unsubscribed contacts along with active ones. |
| Brevo | Emails sent | Tracks volume, so the list can grow without the price moving. |
| Nitrosend | Emails sent | Tracks volume, so the list can grow without the price moving. |
| Bento | Active users | Counts anyone subscribed or with an event in the last thirty days, mailed or not. |
- Contacts held: the bill tracks list size, so a large list mailed once a quarter costs more than a small one mailed daily. Mailchimp, ActiveCampaign, Klaviyo, MailerLite, GetResponse, Loops, Encharge, Omnisend, and Drip all work this way.
- Emails sent: the bill tracks volume, so the list can grow without the price moving. Brevo and Nitrosend both work this way.
- Active users: the bill tracks anyone with recent activity, mailed or not. Bento counts anyone subscribed or with an event in the last thirty days.
The meter is the only thing that predicts your bill a year out, because a drip programme grows on two axes at different speeds. A list that doubles and a sequence that goes from four emails to nine are the same programme getting bigger, and on a contact-metered plan the first costs you while the second is free. Flip the meter and the answer flips with it.
What actually gets counted is rarely what you'd guess. On Mailchimp and Drip an unsubscribed person keeps billing, where MailerLite drops unsubscribed and bounced addresses out of the count entirely. GetResponse adds everyone who joined during a month to the count, whether or not they were still on the list at the end of it. Omnisend counts non-subscribers who only ever received an order confirmation.
Whether an agent can run the sequence is a real difference now.
A first-party MCP server is a set of tools a vendor publishes so an AI agent can operate the account directly, with no browser in the loop. For a drip programme that means building the sequence, editing a step, checking what a segment resolves to, and testing a send all become things you ask for rather than click through.
| Platform | MCP server | What it can write |
|---|---|---|
| Brevo | Broad, official | Campaigns, flows, segments, and templates, both read and write. |
| MailerLite | Broad, official | Campaigns, flows, segments, and templates, both read and write. |
| Klaviyo | Broad, official | Campaigns, flows, segments, and templates, both read and write. |
| Omnisend | Broad, official | Campaigns, flows, segments, and templates, both read and write. |
| Loops | Narrow, official | Contacts, events, and sends; campaign creation is absent or lands as a draft for a person to approve. |
| Bento | Narrow, official | Contacts, events, and sends; campaign creation is absent or lands as a draft for a person to approve. |
| Mailchimp | Transactional only | Its only official server covers the transactional product, not the marketing one. |
| Drip | None official | No server of its own; an agent reaches it through somebody else's wrapper. |
| GetResponse | None official | No server of its own; an agent reaches it through somebody else's wrapper. |
This stopped being theoretical over the last eighteen months, and the servers differ enormously in reach. I'd check what a vendor's server can write rather than what it can read, because reading is the half every one of them ships first. Brevo, MailerLite, Klaviyo, and Omnisend publish broad ones that write as well as read, covering campaigns, flows, segments, and templates. Loops and Bento publish narrower ones shaped around contacts, events, and sends, where campaign creation is absent or lands as a draft for a person to approve. Mailchimp's only official server covers its transactional product rather than the marketing one, and Drip and GetResponse have none of their own, so an agent reaches either through somebody else's wrapper.
Where they all run out is the same place, and that's the more useful finding. Deliverability checks, approvals, and billing appear in none of these published tool lists, and those are the three operations that end an automation. That isn't an oversight in four separate roadmaps. A tool list is a map of what a vendor could expose from a product whose primary surface is a screen, so the agent inherits the parts that were already API-shaped and stops dead at the parts that were only ever a button. An agent that hits one of them stops and hands the work back to you. Nitrosend was built the other way round. It's an AI-native email platform where every capability is an API endpoint and an MCP tool before it's a screen.
Sequences break on the deliverability side, not in the builder.
A drip campaign is repeated automated sending to people who didn't ask for it today, which is exactly the shape mailbox providers police. Google asks bulk senders to keep the spam rate reported in Postmaster Tools below 0.30%, to authenticate with SPF and DKIM plus DMARC, and to support one-click unsubscribe on marketing and subscribed messages alongside a visible unsubscribe link, per Google's sender guidelines. Yahoo asks for the same spam-rate ceiling, the same authentication, a DMARC policy of at least p=none, and unsubscribes honoured within two days, in its own sender best practices. The header pair behind one-click unsubscribe is a published standard, defined in RFC 8058.
Every platform above can put those headers on a message. What varies is what happens next. A sequence is the one thing on an email platform that keeps sending while nobody is watching, so suppression has to be global to the account rather than per campaign, and an unsubscribe at step two has to stop step three the same day. Ask a vendor where the complaint rate and the bounce split are shown before you ask what the builder looks like. Frequency is the variable that breaks this fastest, in my experience: complaint rates spike hardest when a sequence takes a quiet list to three or four emails a week overnight, which is exactly what an unthrottled drip does to anyone trickling in.
Read the head-to-head, one at a time.
These four have a full comparison against Nitrosend: both pricing ladders side by side, the migration steps in order, and a section on what that vendor does better.
The rest sit in the comparison index.
If the meter is what you've decided to compare on, the cheapest way to settle it is to run one real sequence and watch what the number does. Start on the free tier: 8,000 emails to begin with, then 500 a month, unlimited contacts, and the MCP, API, and CLI all switched on with no card. Point one message type at it, give it a fortnight, and read the pricing ladder once you know what your volume looks like.
Sources
- Google, Email sender guidelines: the 0.30% spam-rate ceiling in Postmaster Tools, the SPF, DKIM, and DMARC requirement, and one-click unsubscribe on marketing and subscribed messages.
- Yahoo Sender Hub, best practices: the 0.3% spam-rate ceiling, SPF and DKIM, a DMARC policy of at least p=none, 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
A drip campaign is one shape of email automation: a series of messages that starts on a trigger and runs to a schedule, like a five-email onboarding sequence. Email automation is the whole category, and it covers things a drip sequence isn't, such as a single transactional receipt, a branch that routes someone on what they clicked, or a flow that waits indefinitely for an event that may never arrive. Every platform on this page builds both. In practice the word drip just signals that the sequence has a fixed length and a fixed cadence.
Fewer than most people plan for, and the count matters far less than what ends it. I've watched onboarding sequences run to four or five messages before the genuinely useful things to say run out, after which the complaint rate starts doing the talking. The better question is the exit condition: what someone has to do for the sequence to stop, and whether an unsubscribe at step two reliably stops step three. A four-email sequence that exits cleanly beats a twelve-email one that doesn't.
It depends which axis your programme grows on. If it's list size, MailerLite's Comfort plan opens at $12 a month for 500 subscribers and Mailchimp's Essentials at $13 for up to 500 contacts, though Essentials caps automation at four flow steps. If it's volume, Brevo's Starter is $9 a month from 5,000 emails and Nitrosend's Pro is $20 for 20,000 emails with unlimited contacts. Work out whether your list or your monthly send volume is the bigger number before you compare any two of them.
Yes, though every free tier here is small. GetResponse gives 500 contacts, 2,500 newsletters a month, and published workflows, with a badge on every message. MailerLite gives 250 subscribers and 2,500 emails a month, Mailchimp 250 contacts and 500 sends, and Omnisend 250 contacts and 500 emails with all core features on. Nitrosend's free tier is 8,000 emails to start and then 500 a month, with unlimited contacts and full MCP, API, and CLI access. ActiveCampaign, Encharge, Drip, and Bento have no free plan at all, only a trial.
No. A drip sequence needs a contact record, a trigger, and a way to branch, and every platform on this page has all three without a sales pipeline attached. A CRM earns its place when a person is going to act on what the sequence learns, which is a B2B pattern rather than an ecommerce or newsletter one. ActiveCampaign is the one to look at if you want both in one tool, though the pipeline layer with deal records and lead scoring sits in an add-on rather than inside the plan price.
Klaviyo, if the sequence has to know what someone bought and the list is large enough to justify the ladder: product feeds, predictive analytics, and revenue attributed back to the order all assume a store exists. Omnisend is the cheaper way in and carries unlimited user seats on every plan, Free included. Drip is worth a look if you want one plan with no feature tiers. Nitrosend specialises in email and connects to a store through webhooks and the REST API rather than a first-party product-feed sync.
Not usually, and it's worth checking before you plan around it. A published server is normally a fixed list of tools written over part of the API, so an agent gets what the vendor chose to expose rather than everything the platform can do. Omnisend's four tools are the exception, reaching the whole API rather than a fixed set, and Bento's hosted endpoint lands every new broadcast as a draft for a person to send. Plan matters too: MailerLite's API and MCP sending both need a paid plan. On Nitrosend, MCP, REST, and CLI cover the same surface, and all three are switched on from the free tier with no card.
Four things, in this order. Whether contacts export with their custom fields and consent status rather than just addresses. Whether the automations export at all, because on most platforms a sequence is rebuilt by hand rather than ported. What the new bill is counted on, since the meter changes and a list that was free to hold may stop being free. Then whether the sending path changes on the same day as the platform, which is what makes a bad first week impossible to diagnose. BYO sending keys on Nitrosend's Pro plan and above cover Amazon SES, Resend, Postmark, Mailgun, and SendGrid.