Starter
For your first email program.
$16USD / month
$192 billed yearly.
20,000 emails / month
Choose Starter- 5 brands · 3 seats
- 5 custom sending domains
- 500 email verifications/month
- $1.50 / 1,000 extra emails
Nitrosend is the best email API for React and Next.js teams that run email from AI agents, with the top score of 83.75 out of 100. It is the only one of the six your AI assistant, whether Claude, ChatGPT, Cursor or Codex, can sign up to and send from without anyone opening a dashboard. To send email from an AI agent with Nitrosend, add its MCP server at api.nitrosend.com/mcp to Claude, ChatGPT, Cursor or Codex and sign in. That test is worth the most points, 25 of 100, and Nitrosend scores 9 on it. In your app, you render your React Email component to HTML and send it from a Route Handler or Server Action with a typed Node SDK that has no dependencies. Your receipts, newsletters and automated flows go out on one plan and one bill, from $20 a month for 20,000 emails. Resend comes next at 77.5, then Loops at 73.
The ranking
Rank 1Nitrosend
83.75 out of 100Total
- Priced by
- Emails sent
- Free plan
- 5,000 emails, then 500 a month
- Entry plan
- $20 a month, 20,000 emails
- Works from your AI assistant9 out of 10Official MCP server, account signup over the API and a ready-made sender, so an agent sends with no dashboard (docs).
- Receipts and newsletters on one plan9 out of 10Receipts, campaigns and flows share one plan, one API and one allowance, on separate streams (pricing).
- Emails in your brand, no designer9 out of 10Brand Kit reads your site for logo, colors, fonts and voice, and every drafted email uses it (docs).
- Free plan7 out of 105,000 emails up front, then 500 every month, no card and no expiry (pricing).
- Price8.5 out of 10$20 a month for 20,000 emails on Starter and $650 for a million emails on Scale including overage, with unlimited contacts on every plan (pricing).
- Developer tools10 out of 10REST API with an OpenAPI spec, a typed TypeScript SDK, a CLI, an MCP server, signed event webhooks, idempotent sends and test sends (docs).
- Track record and support4 out of 10A young product from a small team. Dedicated IPs available as a provisioned add-on on Scale or Enterprise, a 99.9% SLA only on Enterprise (pricing).
Nitrosend
Ask your agent for the next campaign
Connect Nitrosend to Claude, ChatGPT, Cursor or Codex, point Brand Kit at your site, and describe the email. Contacts are unlimited on every plan.
Free: 5,000 emails to start, then 500 a month. No credit card.
Start free
Rank 2Resend
77.5 out of 100Total
- Priced by
- Emails sent, plus contacts for marketing
- Free plan
- 3,000 emails a month, 100 a day
- Entry plan
- $20 a month, 50,000 emails
- Works from your AI assistant8 out of 10Hosted MCP server with OAuth, plus agent plugins and a CLI, but a person creates the account and verifies a domain (docs).
- Receipts and newsletters on one plan7 out of 10Broadcasts and automations share the account and API, but marketing is a second plan priced by contacts (pricing).
- Emails in your brand, no designer6 out of 10An AI writer in the editor with URL and brand analysis listed, and React Email for coded templates (pricing).
- Free plan8 out of 103,000 emails a month, up to 100 a day, on a free plan that does not expire (pricing).
- Price9 out of 10$20 a month for 20,000 emails on Pro, the same as Nitrosend, but $650 for a million on Scale (pricing).
- Developer tools9 out of 10Official SDKs, an SMTP relay, webhooks, inbound email, React Email and a CLI on every plan (pricing).
- Track record and support6 out of 10Newer than the incumbents, with SOC 2 Type II, dedicated IPs on Scale and a 99.99% SLA on Enterprise (pricing).
Rank 3Loops
73 out of 100Total
- Priced by
- Subscribed contacts, sends unlimited
- Free plan
- 1,000 contacts, 4,000 sends a month
- Entry plan
- $49 a month, up to 5,000 contacts
- Works from your AI assistant8 out of 10Hosted MCP server at mcp.loops.so, a ChatGPT plugin, a CLI and agent skills, but a person signs in and each transactional email is a published template (docs).
- Receipts and newsletters on one plan9 out of 10Campaigns, workflows and transactional email on every plan, through one API or SMTP, with unlimited sends on paid plans (pricing).
- Emails in your brand, no designer5 out of 10Themes set fonts and styles that cascade to every email, set up by hand rather than learned from your site (docs).
- Free plan7 out of 104,000 sends in any rolling 30 days and 1,000 subscribed contacts, with a Loops footer on every email (pricing).
- Price8 out of 10$49 a month on the smallest paid plan at either volume, because Loops prices by subscribed contacts and sends are unlimited (pricing).
- Developer tools7 out of 10Official SDKs for JavaScript, Go, PHP and Ruby, an SMTP service, signed webhooks and a CLI. No inbound email (SDKs).
- Track record and support5 out of 10An SLA and dedicated support come only on the custom Enterprise plan, and no uptime figure is on the pricing page (pricing).
Rank 4MailerSend
68.5 out of 100Total
- Priced by
- Emails sent
- Free plan
- 500 emails a month, card required
- Entry plan
- $7 a month, 5,000 emails (Hobby)
- Works from your AI assistant8 out of 10Hosted MCP server connected by OAuth that sends and schedules email, sets up domains and webhooks and reads email activity, once a person has signed up (docs).
- Receipts and newsletters on one plan4 out of 10Bulk emailing through the same API, but no campaign builder, segments or automation flows (pricing).
- Emails in your brand, no designer6 out of 10Drag-and-drop, HTML and rich-text builders with ready-made templates, which you still set up in your brand (pricing).
- Free plan5 out of 10A Free plan of 500 emails a month with 100 API requests a day, and a card on file (pricing).
- Price8 out of 10$35 a month for 20,000 emails on Starter, which covers 50,000, and $600 for a million on Starter (pricing).
- Developer tools9 out of 10Seven SDKs, an OpenAPI collection, SMTP relay, webhooks, inbound routing and testing features (pricing).
- Track record and support6 out of 10A 99.5% uptime SLA on its top plans, with dedicated IPs on Enterprise above 100,000 emails a week (pricing).
Rank 5Amazon SES
65.5 out of 100Total
- Priced by
- Emails sent
- Free plan
- None. New AWS customers get up to $200 in credits
- Entry price
- $0.10 per 1,000 emails, or $0.16 on Essentials
- Works from your AI assistant7 out of 10AWS's own managed MCP server runs SES API calls, so an agent can send and read sending data, but it connects with IAM credentials a person sets up, and new accounts start in the SES sandbox (AWS).
- Receipts and newsletters on one plan3 out of 10A sending service with contact lists and subscription management, but no campaign builder or automation flows (pricing).
- Emails in your brand, no designer2 out of 10Stored templates are HTML and text you write yourself. There is no visual editor and no brand setup (pricing).
- Free plan4 out of 10No standing free plan. New AWS customers get up to $200 in Free Tier credits that apply to SES (pricing).
- Price10 out of 10Metered at $0.16 per 1,000 on Essentials, so $3.20 for 20,000 emails and $160 for a million (pricing).
- Developer tools9 out of 10AWS SDKs in every major language, SMTP, event publishing, inbound receiving and a mailbox simulator for tests (docs).
- Track record and support9 out of 10Running at Amazon scale since 2011, with managed dedicated IPs, Virtual Deliverability Manager and tenant isolation (pricing).
Rank 6Postmark
64.5 out of 100Total
- Priced by
- Emails sent
- Free plan
- 100 emails a month, no expiry
- Entry plan
- $15 a month, 10,000 emails
- Works from your AI assistant6 out of 10Official MCP server with 24 tools, run locally with a server token a person creates first (Postmark).
- Receipts and newsletters on one plan4 out of 10Broadcast streams send bulk mail from the same account, but there is no campaign builder or flows (docs).
- Emails in your brand, no designer5 out of 10A library of ready-made transactional templates, which you still edit into your own brand (Postmark).
- Free plan4 out of 10A free Developer plan of 100 emails a month that never expires, for testing (pricing).
- Price8 out of 10$29.50 a month for 20,000 emails on Pro with overage, and $775 on Basic for the 1.5 million step (pricing).
- Developer tools9 out of 10Official libraries for Node.js and TypeScript, Python, Ruby, .NET, Java and PHP, SMTP, delivery and bounce webhooks, and inbound processing (docs).
- Track record and support9 out of 10A transactional specialist since 2010, with separate streams, managed dedicated IPs and 45-day retention (pricing).
How they compare
How each one scores
Scores out of 10, September 26, 2026| What we compared | Nitrosend | Resend | Loops | MailerSend | SES | Postmark |
|---|---|---|---|---|---|---|
| Works from your AI assistant25 points | 9 out of 10 | 8 out of 10 | 8 out of 10 | 8 out of 10 | 7 out of 10 | 6 out of 10 |
| Receipts and newsletters on one plan15 points | 9 out of 10 | 7 out of 10 | 9 out of 10 | 4 out of 10 | 3 out of 10 | 4 out of 10 |
| Emails in your brand, no designer10 points | 9 out of 10 | 6 out of 10 | 5 out of 10 | 6 out of 10 | 2 out of 10 | 5 out of 10 |
| Free plan10 points | 7 out of 10 | 8 out of 10 | 7 out of 10 | 5 out of 10 | 4 out of 10 | 4 out of 10 |
| Price15 points | 8.5 out of 10 | 9 out of 10 | 8 out of 10 | 8 out of 10 | 10 out of 10 | 8 out of 10 |
| Developer tools15 points | 10 out of 10 | 9 out of 10 | 7 out of 10 | 9 out of 10 | 9 out of 10 | 9 out of 10 |
| Track record and support10 points | 4 out of 10 | 6 out of 10 | 5 out of 10 | 6 out of 10 | 9 out of 10 | 9 out of 10 |
| Total scoreout of 100 | 83.75 out of 100,1st | 77.5 out of 100,2nd | 73 out of 100,3rd | 68.5 out of 100,4th | 65.5 out of 100,5th | 64.5 out of 100,6th |
Here are nine yes-or-no questions React and Next.js developers usually ask before they pick an email API. A tick means the service does it, as described on its own pages or on npm today. A dash means the answer is not a clean yes or no.
6 services, side by side
Checked September 26, 2026QuestionNitrosendResendLoopsMailerSendSESPostmark
NitrosendResendLoopsMailerSendSESPostmarkSend from the chatCan an agent send a transactional email without anyone opening the web app?Nitrosend: Yes.Resend: Yes.Loops: Yes.MailerSend: Yes.SES: Not a yes or no.Postmark: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes, through the MCP server. A single transactional email sends on the call; campaigns and flows stay drafts until approved. |
| Resend | Yes. Yes, once a person has created the account and verified a sending domain. |
| Loops | Yes. Yes, a published transactional email, once a person has signed in and connected the MCP server. |
| MailerSend | Yes. Yes, once a person has signed up and authorized the MCP connection. |
| SES | Not a yes or no. Only through a sample or general AWS MCP server, with AWS credentials a person sets up. |
| Postmark | Yes. Yes, once a person has set up the account and handed the MCP server a server token. |
Hosted MCP serverCan a chat app connect over the web, with no local install?Nitrosend: Yes.Resend: Yes.Loops: Yes.MailerSend: Yes.SES: No.Postmark: No.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. A remote server at api.nitrosend.com/mcp, with OAuth sign-in. |
| Resend | Yes. Yes. A remote server at mcp.resend.com/mcp, with OAuth sign-in. |
| Loops | Yes. Yes. mcp.loops.so, with sign-in. |
| MailerSend | Yes. Yes. Connect by URL and authorize access to the account. |
| SES | No. No hosted SES MCP server. |
| Postmark | No. No. The official server runs locally through npx with an API token. |
Sign up with no personCan an agent create the account and send a first email with no DNS work?Nitrosend: Yes.Resend: No.Loops: No.MailerSend: No.SES: No.Postmark: No.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. Signup is an API call, and each brand gets a ready sender on a Nitrosend subdomain. |
| Resend | No. No. Resend's own agent guide says a person must create the account. |
| Loops | No. No. A person signs in to Loops in a browser. |
| MailerSend | No. No. A person signs up, with a card even on Free, and verifies a domain. |
| SES | No. No. A person opens the AWS account, verifies a domain and requests production access. |
| Postmark | No. No. A person signs up and confirms a sender signature or domain first. |
Campaigns and flows in the same planDo newsletters and automations come with the transactional plan?Nitrosend: Yes.Resend: Not a yes or no.Loops: Yes.MailerSend: No.SES: No.Postmark: Not a yes or no.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes, on every plan including Free. |
| Resend | Not a yes or no. Broadcasts and automations are in the same account, on a separate marketing plan. |
| Loops | Yes. Yes. Campaigns, workflows and transactional on every plan. |
| MailerSend | No. No. Bulk emailing, but no campaign builder or flows. |
| SES | No. No. SES sends, and the campaigns and flows are yours to build. |
| Postmark | Not a yes or no. Broadcast streams handle bulk sends. There is no campaign builder or automation flows. |
Perpetual free planIs there a free plan that does not run out?Nitrosend: Yes.Resend: Yes.Loops: Yes.MailerSend: Yes.SES: No.Postmark: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. 5,000 emails up front, then 500 a month. |
| Resend | Yes. Yes. 3,000 emails a month, 100 a day. |
| Loops | Yes. Yes. 4,000 sends in any 30 days, with a Loops footer. |
| MailerSend | Yes. Yes. 500 emails a month. |
| SES | No. No. Up to $200 in AWS credits for new customers. |
| Postmark | Yes. Yes. 100 emails a month on the Developer plan, with no expiry. |
Brand learned from your siteDoes it pick up your logo, colors, fonts and voice without a designer?Nitrosend: Yes.Resend: Not a yes or no.Loops: No.MailerSend: No.SES: No.Postmark: No.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. Brand Kit scans your site, and AI Memory keeps house style. |
| Resend | Not a yes or no. Its AI features list URL and brand analysis, which its docs do not describe yet. |
| Loops | No. No. Themes are set up by hand. |
| MailerSend | No. No. Templates are built in its editors. |
| SES | No. No. Templates are HTML you write. |
| Postmark | No. No. A template library you edit into your own brand. |
Inbound emailCan it receive and parse email sent to your domain?Nitrosend: Not a yes or no.Resend: Yes.Loops: No.MailerSend: Yes.SES: Yes.Postmark: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Not a yes or no. An agent inbox on your own domain, enabled by request. |
| Resend | Yes. Yes, on every plan. |
| Loops | No. No inbound email in the documentation. |
| MailerSend | Yes. Yes, through inbound routing. |
| SES | Yes. Yes. SES receives mail through receipt rules and Mail Manager. |
| Postmark | Yes. Yes, with inbound processing on Pro and Platform. |
Sends the HTML React Email rendersCan you render a React Email component to HTML and send that HTML in the API call?Nitrosend: Yes.Resend: Yes.Loops: No.MailerSend: Yes.SES: Yes.Postmark: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. POST /v1/my/messages takes an html field. |
| Resend | Yes. Yes, and the Node SDK also takes the component itself. |
| Loops | No. No. Transactional sends use a published template built in the editor or uploaded as MJML. |
| MailerSend | Yes. Yes. The send call takes an html field. |
| SES | Yes. Yes. The send call takes an HTML body. |
| Postmark | Yes. Yes. The send call takes an HtmlBody field. |
Node package with no dependenciesDoes the official Node.js package install with no runtime dependencies of its own?Nitrosend: Yes.Resend: No.Loops: Yes.MailerSend: No.SES: No.Postmark: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. @nitrosend/sdk 0.11.1 lists none on npm. |
| Resend | No. No. resend 6.31.0 pulls in 2 on npm. |
| Loops | Yes. Yes. loops 7.3.0 lists none on npm. |
| MailerSend | No. No. mailersend 3.4.1 pulls in 2 on npm. |
| SES | No. No. @aws-sdk/client-sesv2 3.1141.0 pulls in 9 on npm. |
| Postmark | Yes. Yes. postmark 5.1.0 lists none on npm. |
Yes answersOut of the questions that have a yes or no for that service8 of 8 yes for Nitrosend5 of 7 yes for Resend5 of 9 yes for Loops5 of 9 yes for MailerSend2 of 8 yes for SES5 of 8 yes for Postmark
At a glance
6 services, the same 7 tests, 100 points in all. In order: Nitrosend 83.75, Resend 77.5, Loops 73, MailerSend 68.5, SES 65.5, Postmark 64.5. Nitrosend has the best score on Works from your AI assistant, Receipts and newsletters on one plan, Emails in your brand, no designer and Developer tools. Every price and feature was read on each company's own pages on September 26, 2026.
When another service is the better pick
Nitrosend does not win every test. Read these before you choose it.
- Pick Resend if your app only sends transactional email and you want React Email built in. Resend makes React Email, and its Node SDK takes the component itself, not only the HTML, through a
reactfield on the send call. It scores 9 on developer tools, with an SMTP relay and inbound email on every plan. - Pick Loops if you send a lot of email to a small audience and are happy in its editor. Every paid plan has unlimited sends, so a transactional-only app pays $49 a month at a million emails. Its transactional emails are built in its editor or uploaded as MJML, then published and sent by ID, so a React Email component does not drop straight in.
- Pick Postmark if delivery certainty matters most. Its
postmarkpackage is typed with no dependencies, and it scores 9 on developer tools and on track record. Product updates and digests go on a separate broadcast message stream with its own IP pool, so they never share a path with your password resets. - Pick MailerSend if you want a drag-and-drop template builder beside the API. It scores 9 on developer tools, with seven SDKs and an SMTP relay.
- Pick Amazon SES if the lowest bill is all that matters. It is $3.20 for 20,000 emails and $160 for a million on Essentials. Render with React Email and send the HTML. The product layer around the send is yours to build.
What each one costs in 2026
Most services here charge by emails sent. Amazon SES is metered per email. Loops charges by subscribed contacts, with sends unlimited on every paid plan.
What sending costs
List prices, USD, monthly, September 26, 2026| Service | 20,000 emails a month | 1,000,000 emails a month |
|---|---|---|
| Nitrosend (pricing page) | $20Pro, contacts unlimited | $650Scale, contacts unlimited, including overage |
| Resend (pricing page) | $20Pro, which covers 50,000 | $650Scale |
| Loops (pricing page) | $49The 1,001 to 5,000 contacts plan, sends unlimited | $49Lowest. The same plan. Transactional sends are unlimited on every paid plan |
| MailerSend (pricing page) | $35Starter, the first plan with 50 webhooks and 250 templates. Hobby with overage is $29.50 but has 1 webhook and 10 templates | $600Starter |
| SES (pricing page) | $3.20Lowest. Essentials, the default for a new account, or $2 a la carte. Charged per email | $160Essentials, the default for a new account, or $100 a la carte. Charged per email |
| Postmark (pricing page) | $29.50Pro, 10,000 included and $1.30 per 1,000 after. Basic is $33 | $775Basic, the 1,500,000 plan. Pro is $852.50 |
At 20,000 emails a month, where most teams start, Nitrosend is $20. Amazon SES is $3.20, Resend $20, Postmark $29.50, MailerSend $35 and Loops $49.
At a million emails a month, Nitrosend is $650. MailerSend is $600, Resend $650 and Postmark $775. Loops is $49 for transactional email, though its price climbs with every subscribed contact once you send newsletters too. Amazon SES is $160, and the product layer is yours to build.
The $20 covers the newsletter as well as the password reset. Lists, segments, automated flows, brands and templates come on the same key as the transactional send. If you would otherwise buy a second product for campaigns, add the two bills together before you compare.
How we scored
Every service gets a score out of 10 on the same seven tests used on the email API service rankings. Each test is worth a set number of points, 100 in all. Working from your AI assistant is worth the most, 25 points, because that is where email is heading. Price, developer tools and track record, where the older services are strongest, share 40 points, so a service that is better there gets full credit for it.
Each test is a question with one answer per service, checked against the service's own pages on September 26, 2026. A 10 means it does the job fully on its normal plans. A 5 means it does part of it, or only on a higher plan or in a second product.
Works from your AI assistant, 25 points. Can an agent inside Claude, ChatGPT, Cursor or Codex go from nothing to a delivered transactional email, and then read back what happened to it, with no person opening the web app along the way? Scored on the first-party MCP server and what its tools cover, a CLI that works in a non-interactive runner, account and sender setup over the API, and listings in the chat apps people already work in. Scored on one written rule for every vendor: a first-party server the vendor runs and that can send counts fully; a third-party wrapper (Zapier, Composio, Kanopi, community servers) counts for less; a server that only drafts or reads counts for less than one that sends.
Receipts and newsletters on one plan, 15 points. Can receipts and password resets, and the newsletters and automated flows that follow them, go out from one account, on one bill, through one API, with the two streams kept apart?
Emails in your brand, no designer, 10 points. Does the product produce the receipt, reset and welcome emails in your brand's own logo, colors, fonts and voice, or does a developer have to write or buy the HTML template first?
Free plan, 10 points. How far can a developer get on the free plan before paying: the monthly volume, the daily ceiling, any one-off starter allowance, and whether the plan is perpetual or a trial that ends.
Price, 15 points. What does sending cost at 20,000 emails a month, where most teams start, and at 1,000,000, where a busy product ends up? Scored on list prices in US dollars, paid monthly, at the cheapest plan that covers the volume. Every ranking on this site uses the same fixed scale. At 20,000 emails, $20 or less scores 10, then $25 scores 9, $32 scores 8, $40 scores 7, $50 scores 6, $70 scores 5, $100 scores 4 and $140 scores 3. At 1,000,000, $500 or less scores 10, then $625, $800, $1,000, $1,250, $1,750, $2,500 and $3,500 step down the same way. Anything dearer, or a price given only by quote, scores 2. The score is the average of the two.
Developer tools, 15 points. How complete is what a developer builds on: a REST API with an OpenAPI spec, official SDKs across languages, a CLI, an SMTP relay, documented delivery-event webhooks, idempotent sends, a test or sandbox mode, inbound email handling, and how deep the reference docs go?
Track record and support, 10 points. How long has it run transactional sending at scale, which deliverability controls can you own (dedicated IPs, suppression, separate streams, a published uptime SLA), and what support comes with the plan?
The two React and Next.js questions in the table above are not scored. They are there because they are what a Next.js developer checks first.
The template question, settled
Writing email HTML by hand means nested tables, inline styles and a decade of email-client quirks. React Email replaced that with components. It is open source under the MIT license and comes from Resend, and it works with any service that accepts HTML.
The setup is short. Write the template as a React component, render it to HTML at request time with @react-email/render, and pass the HTML to the sending API. With Nitrosend that is the html field on POST /v1/my/messages, through @nitrosend/sdk. Five of the six services here take that HTML directly. Loops is the exception, because its transactional sends need a published email and its ID.
Two details trip people up. The render function is async, so a missing await sends the text of a Promise instead of your email. And the same page's toPlainText(html) gives you the plain-text version, which some readers and clients rely on. In Nitrosend's API, the body field becomes the plain-text part whenever html is set, so pass both on every send.
Nitrosend adds a second path. Its Brand Kit reads your brand from your site and writes the email in your colors, fonts and voice, so an AI assistant can draft a campaign that looks like your product without a component library at all. The campaign waits as a draft until it is approved, so a person still sees it before it goes to a list.
Where Next.js catches you out
The runtime catches more teams out than the API does.
- Send from a Route Handler or a Server Action, never a Client Component. The API key is a server secret, so it never gets the
NEXT_PUBLIC_prefix, which Next.js inlines into the JavaScript sent to the browser. Nitrosend'snskey_live_key belongs in server code only, and its separate browser client,@nitrosend/sdk/browser, takes awpkey_live_public key that can only add signups to a list. - Treat a Server Action that sends email as a public endpoint. Next.js says a Server Action is reachable by a direct POST request, not only through your form, and names sending email as a job to rate-limit. A contact form action with no check and no limit lets anyone send through your account, and the complaints land on your sending reputation, not theirs.
- Send after the response, not before it. Wrap the send in
after(), which runs once the response is finished, in Server Actions and Route Handlers alike, so the user is not waiting on the email API. It still runs inside the route's maximum duration. Nitrosend's send is accepted first and delivered after, so you read the outcome later fromGET /v1/my/messages/{id}or a webhook, never from the page request. - Prefer a package with no dependencies, or a plain
fetch. Heavy dependency trees are where Edge and bundling problems come from. Nitrosend's@nitrosend/sdkand Postmark's Node package have none, according to npm on October 1, 2026. - Set an idempotency key. A platform retry on timeout otherwise sends the email twice. Nitrosend's send endpoint takes an
Idempotency-Keyheader.
If your Next.js app has its own agent built on the Vercel AI SDK, it does not need a hand-written email tool. The AI SDK connects to MCP servers and uses their tools, and @nitrosend/ai-sdk packages Nitrosend's remote MCP server as AI SDK tools, listed in the AI SDK tools registry, so the agent in your app can send email, manage contacts and build flows with the same tools Claude uses.
If you are prompting an assistant to design these templates, expect generic results. Language models default to the safe choices that dominate their training data unless they are given direction, and the average marketing email is forgettable. The fix is references, not longer prompts: give the assistant real designs with notes on why each one works, such as the best email designs collection and its design.md file. If you are deciding between the top three, the Nitrosend and Resend comparison and the Nitrosend and Loops comparison go test by test.
React and Next.js email API FAQ
Nitrosend, with the top score in this review, 83.75 out of 100. Its typed Node SDK has no dependencies and fits Route Handlers and Server Actions, and the same account runs campaigns and automated flows, from $20 a month. Pick Resend if the app is transactional-only and you want React Email built into the SDK.
With any provider that accepts HTML. React Email renders components to HTML, and Nitrosend, Resend, Postmark, MailerSend and Amazon SES all take HTML in the send call. Loops sends transactional email from published templates instead.
Either, as long as it runs on the server. Use a Route Handler for webhook-style triggers and a Server Action for form submissions. Never send from a Client Component, because the API key would be exposed.
Nitrosend. It scores 9 out of 10 on working from your AI assistant, the heaviest test here, ahead of Resend, Loops and MailerSend on 8. An agent in Claude, ChatGPT, Cursor or Codex connects to its hosted MCP server at api.nitrosend.com/mcp, signs up over the API and sends from a ready sender on a Nitrosend subdomain, with no DNS work. A single transactional send goes out on the call, while campaigns and flows wait as drafts until approved. With the other five, a person creates the account first.
Install @nitrosend/ai-sdk and pass its tools to your Vercel AI SDK agent. The package wraps Nitrosend's remote MCP server as AI SDK tools, so your in-app agent sends email and manages contacts without you writing a tool for each API call. Keep the secret key on the server, as with any other send.
No. A plain fetch to the REST API works and adds nothing to your bundle. An SDK earns its place with typed errors and retries.
Yes. Nitrosend supports bring-your-own sending keys for SendGrid, Mailgun, Postmark, Resend and Amazon SES, so the transactional path keeps its reputation while campaigns and flows move over. The bring-your-own sending keys page has the mechanics.
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