These two get cross-shopped because they answer the same sentence — we need an email service our marketing person can also use — from very different sizes of company. MailerSend is a focused product that put a real drag-and-drop builder in front of a competent API. SendGrid is an incumbent platform inside a large communications company, with a feature surface that covers far more and a reputation among its own customers that is more complicated than its market share suggests. The decision usually comes down to two questions: who edits templates, and how many brands you send for.
At a glance
| MailerSend | SendGrid | |
|---|---|---|
| What it is | Email API with a drag-and-drop template builder | Twilio's email platform — API, SMTP, and marketing |
| Published pricing | Free 500/mo (100/day). Starter $35/mo at 50K ($31.50 annual). Professional $110/mo at 50K ($99 annual). Overage from $1.30 per 1,000, falling as plan size grows. | Essentials $19.95 at 50K and $34.95 at 100K. Pro $89.95 at 100K, $249 at 300K, $499 at 700K. Dedicated IP is Pro and above; extra IPs $30/mo. Marketing Campaigns is priced as its own plan, not an add-on. |
| Best for | Mid-market teams who need a template builder a non-engineer can open. | Enterprises wanting one procurement relationship, SMTP everywhere, and marketing in the same console. |
| Watch out for | The free tier is only 500 emails a month, and Professional costs $75/mo more than Starter for identical volume — you are buying seats and retention, not sending. | The free tier died on 27 May 2025, replaced by a 60-day trial at 100/day. Support latency and abrupt account suspensions dominate its public reviews. |
Prices are each vendor's published list prices, verified August 2026. Check the vendor's own page before you sign anything.
Where they actually differ
Who is expected to edit the template
MailerSend
A non-engineer, comfortably. The drag-and-drop builder is a first-class part of the product rather than a checkbox, with variables that an engineer can wire up once and copy that a marketer can change afterwards without a deploy. For a small team where one person writes the code and another writes the words, this removes a recurring source of friction.
SendGrid
Either, awkwardly. There is a design library and a template editor with a templating syntax, and both are perfectly usable, and neither feels like the centre of the product. SendGrid's centre is the sending platform, and the editing experience carries the accumulated compromises of a product that has had to keep many kinds of customer happy for a long time.
What moving up a tier actually buys
MailerSend
Seats, retention and support rather than headroom. The higher plan can cost substantially more than the lower one for identical sending volume, which reads as strange until you understand it as a per-organisation price rather than a per-message one. If you are one developer, the entry tier is the product and the upgrade is not for you.
SendGrid
Infrastructure. The step up unlocks dedicated addresses, subusers and higher-grade support, which are capabilities rather than allowances, and the ladder is structured around what a larger sending operation needs. It is a coherent design and it means a small team can find itself paying for a tier because of one feature buried in it.
Sending for more than one brand
MailerSend
Domains are supported and the model is flat: several verified domains on one account, sharing the same reputation and the same suppression list. For one company with a couple of domains that is correct and simple. For an agency or a platform sending on behalf of many customers, the absence of real separation becomes a problem as soon as one of those customers has a bad list.
SendGrid
The subuser model is the strongest thing SendGrid has and it is genuinely hard to replace. Each subuser has its own credentials, its own reputation, its own suppression and its own reporting, so one tenant's behaviour is isolated from the others. If you send on behalf of customers, this feature alone frequently decides the evaluation before anything else is compared.
Marketing email, and what it costs
MailerSend
Campaign and automation capability lives alongside the transactional API in the same product, which suits the team that wanted one tool. The depth is modest next to a dedicated marketing platform, and modest is often exactly right — most teams comparing these two are not running sophisticated lifecycle programmes, they are sending an announcement every few weeks.
SendGrid
Marketing Campaigns is priced as its own plan rather than bundled, so the one-vendor story costs two subscriptions. That structure is worth noticing at evaluation time, because the comparison people run is usually transactional plan against transactional plan, and the marketing line arrives later as a surprise.
The free tier, and where staging goes
MailerSend
Small. The monthly free allowance is low enough that it is a demonstration rather than an environment, so a staging system needs either a paid plan or a separate capture tool. That is easy to arrange and worth arranging deliberately rather than discovering when a test run exhausts the month.
SendGrid
Gone. The free tier ended in 2025 and was replaced with a time-limited trial, which is the specific event that sent a large number of long-standing SendGrid users looking for alternatives. Any recommendation that assumes a permanent free SendGrid account is describing a product that no longer exists.
Reporting and what you can answer from it
MailerSend
Clean, current and adequate: deliveries, opens, clicks and bounces with enough filtering to answer most questions, presented in an interface that is pleasant to use. It is not built for an analyst who wants to slice a year of history by cohort, and it is not pretending to be.
SendGrid
Deeper and more configurable, with categories, custom arguments and an event webhook carrying enough metadata to rebuild your own analysis downstream. At volume this is the more capable half of the pair by some distance, and the price of that capability is an interface that requires somebody to have learned it.
Support, and what the reviews actually say
MailerSend
Responsive for a company of its size, with the usual caveat that the lowest tier gets the slowest queue. There is no widespread pattern of complaint about arbitrary account action, which is not nothing in a category where that is the dominant fear.
SendGrid
The most consistent theme in public reviews is support latency and abrupt account suspension, and it recurs often enough to be a planning input rather than a rumour. Large platforms are conservative about shared reputation and they act first when a sending pattern looks unusual. If your traffic is spiky, budget for the possibility and keep a fallback path warm.
Validation and list hygiene
MailerSend
There is verification tooling available to check addresses before you send to them, which is the direct answer to the most common cause of a bounce-rate problem. Screening an imported list inside the same vendor that will judge you for bouncing it removes a whole category of self-inflicted incident.
SendGrid
Validation is offered as part of the wider platform, and at the scale SendGrid operates it is backed by a great deal of observed data. The caveat is the one that applies to every validation service: it reduces obvious bounces and cannot tell you whether a valid mailbox belongs to somebody who wants your mail, which is the thing complaint rates actually measure.
Legacy integration surface
MailerSend
SMTP and a modern API, which covers nearly everything. What you will not find is a decade of accumulated third-party integrations built by other people against this specific vendor, because the product has not been around for a decade.
SendGrid
This is the incumbent advantage. Almost every content platform, ecommerce system and internal tool with an email setting has a SendGrid option in a dropdown somewhere, and a great deal of infrastructure was configured against it years ago by people who have since left. That inertia is a real reason accounts stay, independent of whether the product is the best choice today.
Pros and cons, side by side
MailerSend
Strengths
- The builder is the centre of the product rather than a line on the feature list, so a marketer changing a sentence of copy is neither a deploy nor a ticket on somebody else's board.
- Campaign tooling and the transactional API arrive on one subscription, which is the right answer for a team that sends an announcement every few weeks and did not want two suppliers for it.
- SMS sits on the same account, so the day somebody decides verification codes should also go by text does not open a second procurement conversation.
- Address verification comes from the vendor that will also judge your bounce rate, which removes a whole class of self-inflicted incident when you inherit a list.
Trade-offs
- A new account is reviewed by a person before it may send to addresses that are not the owner's, which is sensible anti-abuse and a schedule risk nobody puts into the migration plan.
- Domains sit flat on one account sharing one standing and one suppression record, so a platform sending for many customers has no tenant boundary to lean on at all.
- The free allowance is a demonstration rather than an environment, so a staging system needs either a paid plan or a capture tool arranged on purpose rather than discovered on a Tuesday.
- Stepping up the ladder buys seats, retention and support at identical sending volume, which reads as a pricing error until you understand it as a charge per organisation.
SendGrid
Strengths
- Per-tenant isolation is a primitive here rather than an architecture you assemble, and for an agency or a platform that one capability routinely ends the evaluation before templates come up.
- A dozen years of other people's integrations means the system nobody on your team wrote already has this vendor in a dropdown, with setup instructions somebody else already published.
- Event metadata is rich enough to rebuild your own analysis downstream, which is how a large sender answers the questions a vendor dashboard was never going to answer.
- Sending identity is delegated by CNAME, so signing keys rotate on the vendor's side and nobody has to touch DNS again after the first afternoon.
Trade-offs
- There is no editor a non-engineer will enjoy, so the exact workflow this pair is usually compared to resolve stays precisely where it already was.
- The marketing half is a second plan on a second meter, so a team buying one vendor specifically to avoid two subscriptions acquires two subscriptions.
- Validation, dedicated addresses and the useful support queue each hang off a different rung of the ladder, so a small sender buys an entire tier to get one feature out of it.
- Support latency and abrupt account action dominate its public reviews, and a spiky campaign against a shared pool is exactly the pattern most likely to provoke it.
Pick in thirty seconds
Choose MailerSend if
- A non-engineer needs to change email copy without a deploy, and the builder being good is a requirement rather than a nice extra.
- You are one company with a small number of domains, so tenant-level reputation separation is not something you need.
- You want the transactional API and a modest campaign capability on one plan rather than two subscriptions.
- The interface being modern and pleasant matters, because the people using it are not all engineers.
Choose SendGrid if
- You send on behalf of customers and need per-tenant credentials, reputation and suppression rather than a shared account.
- Something you already run has a SendGrid integration built in, and rewiring it is work nobody has budgeted.
- Your volume and reporting needs are large enough that event metadata and categories are how you would answer questions.
- Procurement prefers a vendor inside a large public company, and that preference is a real constraint rather than a preference.
What actually moves when you switch
In roughly the order you would do it. The expensive parts of an email migration are never the send call.
- Put the account review on the schedule if you are moving toward MailerSend. A person checks a new account before it is allowed to send to addresses other than the owner's, and until that clears you have a trial domain and a sandbox. None of it is unreasonable and none of it is on your calendar, so find out where you sit in the queue before promising anybody a cutover date.
- Decide what replaces the tenant boundary before touching anything else, because this is the part with no destination. Subusers carry their own credentials, standing, suppression and reporting; the other side is a flat account with verified domains and one shared reputation. An agency reproduces that with separate accounts, separate billing and reconciliation inside its own control plane, which is infrastructure with an owner rather than a checkbox on a plan.
- Re-plumb the batch path, because these two batch in opposite directions. One accepts up to a thousand recipient personalizations inside a single synchronous request and tells you immediately what it thought; the other takes a bulk job and hands back an identifier you poll. Your send code changes shape rather than just its hostname, and error handling moves out of the response and into a later lookup.
- Move the DNS in overlap rather than in sequence, because the two authentication models differ over who holds the key. One delegates signing by CNAME so the vendor rotates keys without you; the other expects you to publish its records and keep them current. Both sets coexist happily, so publish the new alongside the old and remove the incumbent's only once the rollback window has genuinely closed.
- Rebuild the templates around whoever will own them afterwards, because this migration usually changes the person rather than only the format. A templating syntax an engineer maintained becomes a builder a marketer edits, or the reverse. Name that person, mark the variables plainly and keep a known-good version to revert to: the failure is never a copy change, it is a deleted placeholder or a removed unsubscribe link.
- Export suppression from every construct that holds one and confirm the destination has somewhere to put each. Complaints, hard bounces and unsubscribes are kept apart on both sides and the categories do not line up one to one, so decide in advance what a category with no counterpart becomes — a manual block, a row in a table you own, or an address you have quietly agreed to start mailing again.
- Read the rate limits per endpoint rather than per account. One side publishes ceilings that differ by endpoint and rise with the plan; the other puts its constraints somewhere else entirely. A nightly job that sat comfortably under a single account-wide number can meet a tighter per-endpoint one on its very first run, in the middle of the night, with nobody watching.
- Move one class of traffic at a time and keep the mail customers would notice missing until the end. Announcements and digests prove the new path cheaply; receipts and password resets move only once the bounce and complaint figures on the new identity have been boring for several consecutive weeks.
Questions to ask before you sign
Put these to a sales rep, or find the answer in the documentation before anyone quotes you a number.
- Who edits the copy in our emails today, and does that person have commit access to the repository?
- Are we one company with several domains, or a platform sending for customers who must not be able to affect each other?
- Has anybody measured our peak requests per second per endpoint, rather than our total messages per month?
- Which of our suppression categories has no equivalent on the other side, and what happens to the addresses in it?
- Is a marketing plan inside the number we have been comparing, or is it a second subscription nobody has quoted yet?
- Who publishes our DNS records, and how quickly can they add a set of them on a Tuesday afternoon?
- Is SMS coming within the year, and would standing up a second vendor for it be acceptable when it does?
Common questions
Why did so many people start looking at SendGrid alternatives in 2025?
The free tier was retired in May 2025 and replaced by a sixty-day trial. A large number of small projects and internal tools had been running on that tier for years, and they all had to make a purchasing decision in the same window. If you are reading a comparison written before that change, its recommendations were formed under different economics and should be re-checked rather than trusted.
What exactly is a subuser and do I need one?
A subuser is an isolated sending identity under one parent account, with its own credentials, reputation, suppression list and reporting. You need it when a bad list belonging to one of your customers must not affect the delivery of everyone else's mail — which is to say, when you are a platform sending on behalf of tenants. A single company with several of its own domains does not need it and should not pay for it.
Can a marketer really edit templates without breaking anything?
With a proper builder, largely yes, and the failure mode is worth designing around. Copy edits are safe. What breaks things is someone removing a variable placeholder, deleting an unsubscribe link or pasting styling that renders badly in one client. Give the non-engineers a template with the variables clearly marked, keep a reviewed version to roll back to, and send a test to yourself after every change — that discipline matters more than which builder you chose.
Should transactional and marketing mail share an account?
They can share a vendor and they should not share a sending identity. Use a separate subdomain for marketing so that reputation, authentication and any blocklisting stay isolated from the mail your product depends on. The failure you are avoiding is concrete and common: a campaign to a stale list raises complaint rates, the domain's reputation drops, and suddenly password resets are landing in spam for everybody.
How hard is it to migrate between these two?
The sending code is a small change; everything around it is not. Templates have to be rebuilt because the syntaxes differ, webhook consumers have to be rewritten against different event shapes, and your suppression list has to be exported and imported before the first send rather than after. Budget for the surrounding work and move one traffic class at a time, keeping the mail your customers would notice missing on the proven path until last.
Is there an approval step before a new account can send?
On MailerSend, yes. A person reviews a new account before it is permitted to send to addresses that are not the account owner's, and until that clears you are working against a trial domain. This is ordinary anti-abuse practice for a vendor whose reputation is shared, and it catches migration plans out because it sits on somebody else's queue rather than yours. Open the account and get through the review while the integration work is still happening, rather than treating it as the last step before cutover. The alternative is a finished migration waiting on an email.
What do we use instead of subusers?
Nothing, in the sense of a direct feature swap — and that is the honest answer rather than a softened one. Per-tenant credentials, reputation, suppression and reporting are a primitive on one side and absent on the other, so a platform reproduces them by running a separate account per tenant, or by accepting that its customers share standing and building enough monitoring to notice quickly when one of them misbehaves. Either path is real engineering with a real owner. If tenant isolation is load-bearing for your business, this dimension decides the comparison and nothing about template editing will outweigh it.
How does each one handle sending to thousands of people?
Differently enough that your send code changes shape. SendGrid takes many recipient personalizations inside one synchronous request and answers immediately, so the natural pattern is to build a large payload and read the response. MailerSend exposes a bulk endpoint that accepts the job and returns an identifier you look up afterwards, so failures surface later and somewhere else. Neither is better; they demand different error handling. If your current code treats the HTTP response as the record of what happened, moving toward the asynchronous side means finding a new home for that logic before the first production run.
Do both sets of DNS records have to be swapped at once?
No, and swapping them at once is how a rollback quietly stops being available. The two vendors authenticate differently — one takes delegated CNAMEs and rotates its own signing keys, the other has you publish and maintain its records — but the records do not conflict with each other and a domain can carry both while you run in parallel. Publish the new set, prove delivery on a subdomain, shift traffic gradually, and remove the incumbent's records only after the last message you might need to rescue has aged out. DNS propagation is the cheapest part of this and the easiest to make irreversible.