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 Postmark alternative for teams that run email from AI over MCP, with the top score of 83.75 out of 100 and 9 out of 10 on working from your AI assistant, the heaviest test here. Postmark sends receipts well and stops there. Nitrosend sends the receipts and the newsletters and automated flows that Postmark leaves out, on one plan and one bill. It is the only one of the eight here your AI assistant, whether Claude, ChatGPT, Cursor or Codex, can sign up to and send from without anyone opening a dashboard, and it writes every email in your brand's colors, fonts and voice. To send email from an AI agent with Nitrosend, add the MCP server at api.nitrosend.com/mcp in Claude, ChatGPT, Cursor or Codex and sign in with OAuth. It costs $20 a month for 20,000 emails and $650 for a million emails on Scale including overage. Resend comes next at 77.5, then Bird (formerly SparkPost) at 76.
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 3Bird (formerly SparkPost)
76 out of 100Total
- Priced by
- Emails sent
- Free plan
- 1,000 emails a month, no expiry
- Entry plan
- $15 a month, 50,000 emails
- Works from your AI assistant8 out of 10Hosted MCP server at mcp.bird.com with OAuth and a CLI, and an agent can sign itself up from the terminal, but it must read an emailed code, and it can only test-send until a sending domain is verified (signup, sandbox).
- Receipts and newsletters on one plan7 out of 10Broadcasts and single sends draw on one email allowance and one bill, with no contact fee. Email automations are in early access, built in the dashboard, with a separate run allowance (automation).
- Emails in your brand, no designer4 out of 10Templates with versions and translations, and React Email rendering. You supply the design (product).
- Free plan6 out of 101,000 emails a month with no time limit and no card, capped at 50 a day (pricing).
- Price10 out of 10$15 a month for 20,000 emails on Startup, and $530 for a million on Growth (pricing).
- Developer tools9 out of 10SDKs for Node, Python, PHP and Go, an SMTP relay, event webhooks, inbound relay webhooks, suppression and a sandbox (API).
- Track record and support7 out of 10SparkPost infrastructure since 2014, now sold as Bird. Dedicated IPs $24.95 each on Growth and above. No SLA 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 5Mailgun
67.5 out of 100Total
- Priced by
- Emails sent
- Free plan
- 100 emails a day
- Entry plan
- $15 a month, 10,000 emails
- Works from your AI assistant6 out of 10Official MCP server for sends, analytics and validation, run locally with an API key. Mailgun offers no hosted version (docs).
- Receipts and newsletters on one plan4 out of 10Mailing lists and a template builder on the sending API, but no campaign builder or automation flows (pricing).
- Emails in your brand, no designer5 out of 10An email template builder and templates API, but the brand design is yours to build (pricing).
- Free plan7 out of 10A free plan of 100 emails a day, one sending domain and one inbound route (pricing).
- Price8 out of 10$33 a month for 20,000 emails on Basic with overage, and $700 for a million on Scale (pricing).
- Developer tools9 out of 10Official SDKs in six languages, SMTP relay, webhooks, inbound routes and a validation API (docs).
- Track record and support9 out of 10A long-running sending API, now part of Sinch, with dedicated IP pools, IP warm-up and an uptime SLA (pricing).
Rank 6Amazon 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 7SMTP2GO
60 out of 100Total
- Priced by
- Emails sent
- Free plan
- 1,000 emails a month
- Entry plan
- $15 a month, 10,000 emails
- Works from your AI assistant7 out of 10A hosted MCP server whose execute-request tool can call any API endpoint, sends included, with an API key a person creates (docs).
- Receipts and newsletters on one plan2 out of 10A sending service for SMTP and API mail, with no campaign builder or automation flows (pricing).
- Emails in your brand, no designer4 out of 10Stored templates through its app and API, but the design is yours to build (docs).
- Free plan6 out of 101,000 emails a month, free for as long as you like, with no credit card (pricing).
- Price9 out of 10$27 a month for 20,000 emails on Starter with overage, and $520 for a million on Professional (pricing).
- Developer tools6 out of 10SMTP relay, REST API, webhooks, templates and testing tools. No SDKs or inbound email in its developer docs (docs).
- Track record and support7 out of 10A dedicated IP on Professional, subaccounts, and ticket, chat and phone support on paid plans (pricing).
Rank 8SendGrid
59.5 out of 100Total
- Priced by
- Emails sent (Email API)
- Free plan
- Trial: 100 a day for 60 days
- Entry plan
- $19.95 a month, 50,000 emails
- Works from your AI assistant3 out of 10No first-party SendGrid MCP server. Twilio's beta MCP server searches API docs and does not send (Twilio).
- Receipts and newsletters on one plan6 out of 10Marketing Campaigns is a separate product with its own plan, priced on contacts stored (Twilio).
- Emails in your brand, no designer5 out of 10Dynamic templates, a design editor and a Designs API, but the design is yours to build (docs).
- Free plan3 out of 10A trial, not a plan: 100 emails a day for 60 days, then pay (pricing).
- Price9 out of 10$19.95 a month for 20,000 emails on Essentials, and $799 for the Pro 1.5 million step (pricing).
- Developer tools9 out of 10SDKs in seven languages, SMTP relay, event webhooks, Inbound Parse and a sandbox mode (docs).
- Track record and support8 out of 10Sending since 2009, owned by Twilio since 2019, dedicated IPs included on Pro (pricing).
How they compare
How each one scores
Scores out of 10, September 25, 2026| What we compared | Nitrosend | Resend | Bird | MailerSend | Mailgun | SES | SMTP2GO | SendGrid |
|---|---|---|---|---|---|---|---|---|
| Works from your AI assistant25 points | 9 out of 10 | 8 out of 10 | 8 out of 10 | 8 out of 10 | 6 out of 10 | 7 out of 10 | 7 out of 10 | 3 out of 10 |
| Receipts and newsletters on one plan15 points | 9 out of 10 | 7 out of 10 | 7 out of 10 | 4 out of 10 | 4 out of 10 | 3 out of 10 | 2 out of 10 | 6 out of 10 |
| Emails in your brand, no designer10 points | 9 out of 10 | 6 out of 10 | 4 out of 10 | 6 out of 10 | 5 out of 10 | 2 out of 10 | 4 out of 10 | 5 out of 10 |
| Free plan10 points | 7 out of 10 | 8 out of 10 | 6 out of 10 | 5 out of 10 | 7 out of 10 | 4 out of 10 | 6 out of 10 | 3 out of 10 |
| Price15 points | 8.5 out of 10 | 9 out of 10 | 10 out of 10 | 8 out of 10 | 8 out of 10 | 10 out of 10 | 9 out of 10 | 9 out of 10 |
| Developer tools15 points | 10 out of 10 | 9 out of 10 | 9 out of 10 | 9 out of 10 | 9 out of 10 | 9 out of 10 | 6 out of 10 | 9 out of 10 |
| Track record and support10 points | 4 out of 10 | 6 out of 10 | 7 out of 10 | 6 out of 10 | 9 out of 10 | 9 out of 10 | 7 out of 10 | 8 out of 10 |
| Total scoreout of 100 | 83.75 out of 100,1st | 77.5 out of 100,2nd | 76 out of 100,3rd | 68.5 out of 100,4th | 67.5 out of 100,5th | 65.5 out of 100,6th | 60 out of 100,7th | 59.5 out of 100,8th |
Here are the seven yes-or-no questions developers usually ask before they pick one of these services. A tick means the service does it, as described on its own pages today. A dash means the answer is not a clean yes or no.
8 services, side by side
Checked September 25, 2026QuestionNitrosendResendBirdMailerSendMailgunSESSMTP2GOSendGrid
NitrosendResendBirdMailerSendMailgunSESSMTP2GOSendGridSend from the chatCan an agent send a transactional email without anyone opening the web app?Nitrosend: Yes.Resend: Yes.Bird: Yes.MailerSend: Yes.Mailgun: Yes.SES: Not a yes or no.SMTP2GO: Yes.SendGrid: Not a yes or no.
| 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. |
| Bird | Yes. Yes, through the hosted MCP server once the workspace exists. Emailing customers needs a verified sending domain. |
| MailerSend | Yes. Yes, once a person has signed up and authorized the MCP connection. |
| Mailgun | Yes. Yes, once a person has created the account and handed the MCP server an API key. |
| SES | Not a yes or no. Only through a sample or general AWS MCP server, with AWS credentials a person sets up. |
| SMTP2GO | Yes. Yes, through its MCP server once a person adds an API key. |
| SendGrid | Not a yes or no. Only by writing code against the API. Twilio's own MCP server searches the docs and does not send. |
Hosted MCP serverCan a chat app connect over the web, with no local install?Nitrosend: Yes.Resend: Yes.Bird: Yes.MailerSend: Yes.Mailgun: No.SES: No.SMTP2GO: Yes.SendGrid: 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. |
| Bird | Yes. Yes. mcp.bird.com, with OAuth sign-in. |
| MailerSend | Yes. Yes. Connect by URL and authorize access to the account. |
| Mailgun | No. No. Mailgun's docs say the server runs locally and no hosted version exists. |
| SES | No. No hosted SES MCP server. |
| SMTP2GO | Yes. Yes. A remote server at developers.smtp2go.com/mcp, with an API key header. |
| SendGrid | No. No. Every SendGrid server on the official MCP registry is community built, none hosted by Twilio. |
Sign up with no personCan an agent create the account and send a first email with no DNS work?Nitrosend: Yes.Resend: No.Bird: Not a yes or no.MailerSend: No.Mailgun: No.SES: No.SMTP2GO: No.SendGrid: 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. |
| Bird | Not a yes or no. An agent can sign itself up through the CLI or the API, but it must read the emailed sign-in code, and until a sending domain is verified it can send only to sandbox addresses and its own workspace members. |
| MailerSend | No. No. A person signs up, with a card even on Free, and verifies a domain. |
| Mailgun | No. No. A person signs up and verifies a sending domain first. |
| SES | No. No. A person opens the AWS account, verifies a domain and requests production access. |
| SMTP2GO | No. No. A person signs up and verifies a sender domain first. |
| SendGrid | No. No. A sender or a domain has to be verified before real sending. |
Campaigns and flows in the same planDo newsletters and automations come with the transactional plan?Nitrosend: Yes.Resend: Not a yes or no.Bird: Not a yes or no.MailerSend: No.Mailgun: No.SES: No.SMTP2GO: No.SendGrid: 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. |
| Bird | Not a yes or no. Broadcasts share the email allowance. Email automations are in early access, with a separate run allowance. |
| MailerSend | No. No. Bulk emailing, but no campaign builder or flows. |
| Mailgun | No. No. Mailing lists and templates, but no campaign builder or flows. |
| SES | No. No. SES sends, and the campaigns and flows are yours to build. |
| SMTP2GO | No. No. Sending only. |
| SendGrid | No. No. Marketing Campaigns is a separate plan, from $15 a month. |
Perpetual free planIs there a free plan that does not run out?Nitrosend: Yes.Resend: Yes.Bird: Yes.MailerSend: Yes.Mailgun: Yes.SES: No.SMTP2GO: Yes.SendGrid: No.
| 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. |
| Bird | Yes. Yes. 1,000 emails a month, no time limit. |
| MailerSend | Yes. Yes. 500 emails a month. |
| Mailgun | Yes. Yes. 100 emails a day. |
| SES | No. No. Up to $200 in AWS credits for new customers. |
| SMTP2GO | Yes. Yes. 1,000 emails a month. |
| SendGrid | No. No. 100 emails a day for 60 days, then a paid plan. |
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.Bird: No.MailerSend: No.Mailgun: No.SES: No.SMTP2GO: No.SendGrid: 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. |
| Bird | No. No. Templates and React Email, and you supply the design. |
| MailerSend | No. No. Templates are built in its editors. |
| Mailgun | No. No. Templates are built in its builder or in HTML. |
| SES | No. No. Templates are HTML you write. |
| SMTP2GO | No. No. Templates are yours to build. |
| SendGrid | No. No. Templates and a design editor, but you supply the design. |
Inbound emailCan it receive and parse email sent to your domain?Nitrosend: Yes.Resend: Yes.Bird: Yes.MailerSend: Yes.Mailgun: Yes.SES: Yes.SMTP2GO: No.SendGrid: Yes.
| Service | Answer |
|---|---|
| Nitrosend | Yes. Yes. An agent inbox on your own domain posts incoming mail to your webhook. |
| Resend | Yes. Yes, on every plan. |
| Bird | Yes. Yes. Inbound domains and relay webhooks. |
| MailerSend | Yes. Yes, through inbound routing. |
| Mailgun | Yes. Yes, through inbound routes. |
| SES | Yes. Yes. SES receives mail through receipt rules and Mail Manager. |
| SMTP2GO | No. No inbound email in its developer docs. |
| SendGrid | Yes. Yes, with Inbound Parse. |
Yes answersOut of the questions that have a yes or no for that service7 of 7 yes for Nitrosend4 of 5 yes for Resend4 of 5 yes for Bird4 of 7 yes for MailerSend3 of 7 yes for Mailgun1 of 6 yes for SES3 of 7 yes for SMTP2GO1 of 6 yes for SendGrid
At a glance
8 services, the same 7 tests, 100 points in all. In order: Nitrosend 83.75, Resend 77.5, Bird 76, MailerSend 68.5, Mailgun 67.5, SES 65.5, SMTP2GO 60, SendGrid 59.5. 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 25, 2026.
When another service is the better pick
Nitrosend does not win every test. Read these before you choose it.
- Pick Resend if you only send transactional email from application code. It scores 9 on developer tools, with official SDKs across languages, an SMTP relay and inbound email. It also scores higher on free plan, 8 to 7, with 3,000 emails a month, and on track record.
- Pick Bird if the first $5 a month matters. It is $15 a month for 20,000 emails, against Nitrosend's $20, though $530 for a million against Nitrosend's $650. It matches Resend on developer tools, and it hosts its own MCP server at mcp.bird.com with OAuth sign-in in the browser.
- 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, which earns it a 10 on price. The catch is that SES is infrastructure rather than a product. The templates, suppression handling and reporting are yours to build, and a person opens the AWS account before anything sends.
- Pick Mailgun if your application takes replies apart. It scores 9 on developer tools, with official SDKs, inbound routes and email validation, and 9 on track record, with dedicated IP pools on Scale and an uptime SLA on every paid plan.
- Pick MailerSend if a marketer edits the templates. It has drag-and-drop, HTML and rich-text editors, with an SMTP relay and inbound routing behind them.
- Pick SendGrid if a long record at scale comes first. It scores 8 on track record, with dedicated IPs included on Pro. Its free offer is a 60-day trial at 100 emails a day, and Marketing Campaigns is a separate product priced on stored contacts as well as volume.
What each one costs in 2026
Every service here charges by emails sent, except two. Amazon SES is metered, at $0.16 per 1,000 on the Essentials plan that new accounts start on. SendGrid bills its Email API on a send-volume slider and Marketing Campaigns on stored contacts and volume, so if you want both, you pay twice, on two different units.
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) | $20Starter, contacts unlimited | $650Scale, contacts unlimited, including overage |
| Resend (pricing page) | $20Pro, which covers 50,000 | $650Scale |
| Bird (pricing page) | $15Startup, which covers 50,000 | $530Growth |
| 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 |
| Mailgun (pricing page) | $33Basic, 10,000 included and $1.80 per 1,000 after | $700Scale |
| SES (pricing page) | $3.20Lowest. Essentials, the default for a new account, or $2 a la carte. Charged per email | $160Lowest. Essentials, the default for a new account, or $100 a la carte. Charged per email |
| SMTP2GO (pricing page) | $27Starter, 10,000 included and $1.20 per 1,000 after | $520Professional |
| SendGrid (pricing page) | $19.95Essentials, which covers 50,000 | $799Pro, the 1,500,000 plan. The 700,000 plan is $499 |
At 20,000 emails a month, Nitrosend is $20. Resend is also $20, SMTP2GO $27, Mailgun $33 and MailerSend $35. Bird at $15 and SendGrid at $19.95 are a few dollars less, and Amazon SES is $3.20.
At a million emails a month, Nitrosend is $650. SMTP2GO is $520, Bird $530, MailerSend $600, Resend $650, Mailgun $700 and SendGrid $799. With Amazon SES the templates, unsubscribe handling and reporting are yours to build. Brevo, a marketing suite that also sends transactional email, is scored on email marketing tests on the Brevo alternatives page instead.
The bigger difference is what the $20 buys. Most email APIs stop at sending a message. Nitrosend's API reference puts lists, segments, automated flows, brands, templates and sending domains behind the same key as its single-call transactional send. Postmark has no campaigns, so if you would otherwise buy a second product for the newsletter, add the two bills together before you compare.
How we scored
Every service gets a score out of 10 on the same seven tests. 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 25, 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?
One thing is not scored: inbox placement. No two of these services publish a comparable deliverability number, so a score there would be a guess dressed up as a measurement.
The older services are reliable, and nothing here questions their uptime. The gap is in who writes the message. Postmark describes itself as built for application email: your code composes each message and Postmark delivers it. An assistant that runs the newsletter as well as the receipts needs the list, the segment and the approval step in the same account it sends from, and that is the job the AI test measures.
When to keep Postmark and when to replace it
Keep it when latency and placement are the job. Message streams keep your broadcasts away from your receipts, so a promotional send cannot damage password-reset delivery, and Postmark's Message Streams page states that transactional and broadcast traffic never intersect, including IP ranges. The activity log shows the real delivery conversation rather than a status word, and inbound parsing is there if you need it.
Replace it, or add to it, for one of three reasons.
Price shape. Postmark is $15 a month for 10,000 emails, checked October 1, 2026, which is $1.50 per thousand at the entry step. That is fine at 10,000 and a line item you notice at a million.
Scope. This is the more common reason. Postmark says it on its own Message Streams page: it is built for application email, and it names what it does not have, which is support for list uploads, a WYSIWYG editor and campaign-based reporting. There is no contact list, no segment and no onboarding sequence with a wait in the middle. So the moment marketing needs a newsletter, you buy a second tool, and nobody sees both halves of what your product sends in one place. Broadcast streams are capped by plan too, at 15 on Basic, 30 on Free and Pro and unlimited on Platform, per its pricing page on October 1, 2026.
George Hartley, Nitrosend's co-founder, built Nitrosend for the wider scope. On The Breakout CEO in August 2026 he described where it had got to: "agents can now create an account, start sending without a human in the loop." If campaigns and flows will be run by an assistant, that is the part to compare, because Postmark by design does not cover it.
Ownership. ActiveCampaign acquired Postmark from Wildbit, announced on May 3, 2022. If you chose it as a neutral transport under a marketing stack you had not committed to, that is worth knowing.
Is there a cheaper alternative to Postmark with the same deliverability?
Not identical, but close enough for most applications. Resend is $20 a month for 50,000 emails, which is $0.40 per thousand against Postmark's $1.50 at the entry step. Amazon SES is an order of magnitude cheaper again and hands you the operational work. The test is whether your email is time critical. If a delayed password reset generates a support ticket, stay with Postmark and cut cost somewhere else. If your volume is mostly digests and notifications, the saving is real and the risk is small.
Can I keep Postmark and add campaigns and flows on top?
Yes, on any paid Nitrosend plan, and it is the lowest-risk option on this page. The connection takes two Postmark tokens, not one: the server token, which sends, and the account token, which Postmark's Domains API requires and describes as "only accessible by the account owner". Handing over that second token is the one step a person has to take, so plan for it before an agent starts the setup. With both, Nitrosend creates and verifies the sending domain in Postmark for you rather than asking you to set it up twice. Sending keeps leaving through your Postmark account on the reputation you have already built, while campaigns, flows, contacts, segments and reporting live in one place. One thing to watch during setup: a domain can exist in Postmark from an earlier attempt without being active in Nitrosend, so check the domain list on both before you send. The bring-your-own sending keys page covers the mechanics.
What replaces Postmark's message streams?
Subdomains, on most of this list. Message streams are Postmark's way of keeping broadcast reputation apart from transactional reputation inside one account, and few competitors build the same thing. The portable version is to send promotional mail from one subdomain and transactional mail from another, so a large campaign that draws complaints cannot damage receipt delivery. Transactional email compared with marketing email covers why the split matters. Nitrosend runs transactional and marketing mail on separate infrastructure and supports the subdomain split. Amazon SES gives you configuration sets with dedicated IP pools, one for marketing and one for transactional mail, which is the same idea with more assembly required.
How to move off Postmark without losing deliverability
Swapping the API takes an afternoon. The reputation takes weeks.
- Export your suppression list first. Take your contacts and sending history too. Bounces and complaints are the part that cannot be rebuilt.
- Save what Postmark remembers. Postmark keeps 45 days of full message content by default, which is how support answers "what did that reset email actually say". Export what you need before you close the account, and ask the replacement how long it keeps the body of each send.
- Authenticate the new sender. Keep both senders in one SPF record during the overlap. The email authentication page has the records and where
p=quarantinebelongs. - Keep the split you already have. If you used message streams, set them up as separate subdomains before you move a single message.
- Move one stream at a time. Start with the least time-critical one. Digests go before receipts.
- Warm the new path. Ramp up rather than switching in one send. How to warm up an email domain has the schedule.
- Test placement before the volume moves. Run an inbox placement test, then watch bounce and complaint rates daily for the first month.
For what happens between your request and the recipient's mail server, the email API hub covers the sending path, and transactional email, in practice covers the messages that ride on it.
Postmark alternatives FAQ
Nitrosend, with the top score in this review, 83.75 out of 100. It adds the campaigns, automated flows and contact lists Postmark does not have, on one plan from $20 a month, and your AI assistant can sign up and send from it without a person opening a dashboard. It can also keep sending through your existing Postmark account. Pick Resend if you only need transactional email from application code, and Amazon SES if unit cost is the whole decision.
Nitrosend, with 9 out of 10 on working from your AI assistant. It has an official MCP server, account signup over the API and a ready-made sender, so Claude, ChatGPT, Cursor or Codex can send with nobody opening a dashboard. Resend and Bird score 8: both host an MCP server with OAuth, but a person creates the account first. MailerSend also scores 8, once a person signs up and authorizes the connection. SMTP2GO scores 7 with a hosted server and an API key, and Amazon SES 7 through AWS's own managed MCP server, on IAM credentials a person sets up. Mailgun scores 6, with a server run locally on an API key, and SendGrid has no first-party MCP server that sends.
Not in the campaign sense. It sends broadcasts through a separate broadcast stream, but its Message Streams page says it offers no list uploads, no WYSIWYG editor and no campaign-based reporting, and there are no automation flows. Keeping marketing out is part of why its deliverability is what it is. If you need both halves, you either run two vendors or use one platform that sends transactional email and campaigns from the same account.
ActiveCampaign, which acquired it from Wildbit in 2022 and said it would remain a standalone product. If you picked Postmark as a neutral transport, that is worth knowing, and it is the same question worth asking about SendGrid under Twilio and Mailgun under Sinch, which the Mailgun alternatives page covers.
Yes, on paid plans. Add your Postmark server token and account token and every send routes through your Postmark account rather than Nitrosend's own sending, so the reputation you built stays where it is. Campaigns, flows, contacts and reporting sit in one place on top of it.
Yes, for the addresses you set up as inboxes. Nitrosend has an Agent Inbox that posts incoming mail to your webhook, and an AI agent can read and reply over MCP, with SPF, DKIM and DMARC results visible per message. Mail it quarantines as spam, a virus or a blocked sender is not posted. If your product receives mail at addresses you cannot set up in advance, keep Postmark or Mailgun for the inbound leg and move the rest.
Add Nitrosend as a connector in Claude with the remote MCP URL https://api.nitrosend.com/mcp, or run claude mcp add --transport http nitrosend https://api.nitrosend.com/mcp in Claude Code, then sign in with OAuth. A receipt goes out when Claude calls the send tool. A newsletter or flow stays a draft until approved. To keep Postmark underneath, connect it as the sending provider first, as described in the Postmark setup guide.
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