Nitrosend is the email API your AI assistant can run, and the better choice than Mailgun overall, with 86 out of 100 against Mailgun's 67.5. 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 with OAuth: a transactional email goes out on the call, while a campaign or flow waits as a draft until it is approved. It wins five of the seven tests: working from your AI assistant, receipts and newsletters on one plan, emails in your brand without a designer, price and developer tools. The two tie on the free plan. Mailgun is a sending API that developers build into their applications, with deep routing and validation tools around it. Nitrosend is built to be run by an agent from inside Claude, ChatGPT, Cursor or Codex, and it writes and sends the welcome series and the newsletter as well as the receipt. It costs $20 a month for 20,000 emails, where Mailgun Basic comes to $33, and $500 for a million, where Mailgun Scale is $700.
Nitrosend vs Mailgun, compared
The quick version: seven yes-or-no questions a team usually asks when choosing between the two. A tick means the product does it as described on its own pages today. A dash means the honest answer is not a yes or a no.
Nitrosend and Mailgun, side by side
Checked October 1, 2026| Question | Nitrosend | Mailgun |
|---|---|---|
| Send from the chatCan an agent send a transactional email without anyone opening the web app? | Yes. Yes, through the MCP server. A single transactional email sends on the call; campaigns and flows stay drafts until approved. | Yes. Yes, once a person has created the account and handed the MCP server an API key. |
| Hosted MCP serverCan a chat app connect over the web, with no local install? | Yes. Yes. A remote server at api.nitrosend.com/mcp, with OAuth sign-in. | No. No. Mailgun's docs say the server runs locally and no hosted version exists. |
| Sign up with no personCan an agent create the account and send a first email with no DNS work? | Yes. Yes. Signup is an API call, and each brand gets a ready sender on a Nitrosend subdomain. | No. No. A person signs up and verifies a sending domain first. |
| Campaigns and flows in the same planDo newsletters and automations come with the transactional plan? | Yes. Yes, on every plan including Free. | No. No. Mailing lists and templates, but no campaign builder or flows. |
| Perpetual free planIs there a free plan that does not run out? | Yes. Yes. 8,000 emails up front, then 500 a month. | Yes. Yes. 100 emails a day. |
| Brand learned from your siteDoes it pick up your logo, colors, fonts and voice without a designer? | Yes. Yes. Brand Kit scans your site, and AI Memory keeps house style. | No. No. Templates are built in its builder or in HTML. |
| Inbound emailCan it receive and parse email sent to your domain? | Not a yes or no. In beta. An agent inbox on your own domain, enabled by request. | Yes. Yes, through inbound routes. |
Nitrosend meets 6 of 6 yes-or-no questions on this page, Mailgun 3 of 7. Rows marked with a dash are not a yes or no question for that product.
How the two score
Seven tests, 100 points in all, the same tests used on every transactional comparison and ranking on this site. Each product gets a score out of 10 on each test, and each test is worth a set number of points. Nitrosend finishes ahead on the total, 86 to 67.5. Mailgun scores higher on one test, track record, and the two tie on the free plan.
Each test, scored
Points out of 100, scores out of 10, October 1, 2026| What we compared | Points | Nitrosend | Mailgun |
|---|---|---|---|
| Works from your AI assistant | 25 | 9 out of 10 | 6 out of 10 |
| Receipts and newsletters on one plan | 15 | 9 out of 10 | 4 out of 10 |
| Emails in your brand, no designer | 10 | 9 out of 10 | 5 out of 10 |
| Free plan | 10 | 7 out of 10 | 7 out of 10 |
| Price | 15 | 10 out of 10 | 8 out of 10 |
| Developer tools | 15 | 10 out of 10 | 9 out of 10 |
| Track record and support | 10 | 4 out of 10 | 9 out of 10 |
| Total score | 100 | 86 out of 100 | 67.5 out of 100 |
Where each one runs out
Rank 1Nitrosend
86 out of 100Total
- Priced by
- Emails sent
- Free plan
- 8,000 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 108,000 emails up front, then 500 every month, no card and no expiry (pricing).
- Price10 out of 10$20 a month for 20,000 emails on Pro and $500 for a million on Enterprise, 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 from Ultra, 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: 8,000 emails to start, then 500 a month. No credit card.
Start free
Rank 2Mailgun
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).
The verdict in short
Nitrosend is the better choice overall, 86 to 67.5, and it is clearly ahead for a team that runs email from an AI assistant or wants receipts and newsletters on one bill.
For a pure sending workload Mailgun's extra jobs matter, and inbound is one of them. George Hartley, Nitrosend's co-founder, has described what agents needed beyond sending. On The Breakout CEO in August 2026 he described agents that signed up and sent on their own, and then: "Oh, actually they need an inbox as well." In the same interview he said "the agents have gotten so much smarter that they, they, they can kind of just work it out now." Weigh inbound by what your product needs today.
Mailgun is only better on one test. Track record and support, 9 to 4, because it is one of the longest-running sending APIs, now part of Sinch, and its plans include dedicated IP pools, automated IP warm-up and an uptime SLA.
At a glance
Nitrosend and Mailgun are scored here on the same 7 tests, 100 points in all: Nitrosend 86 out of 100, Mailgun 67.5 out of 100. Nitrosend takes its best score on Price and Developer tools (10 out of 10) and its lowest on Track record and support (4 out of 10). Mailgun takes its best score on Developer tools and Track record and support (9 out of 10) and its lowest on Receipts and newsletters on one plan (4 out of 10). Mailgun scores higher on Track record and support. Scores are unadjusted, and every Mailgun figure was read on its own site on October 1, 2026.
How we scored
Each test is a question with one answer per product, checked against that product's own pages and independent review sites on October 1, 2026. A 10 means the product does the job fully on its standard plans. A 5 means it does part of it, or does it only on a higher plan or in a second product. Mailgun prices are monthly list prices in US dollars, read from its own pricing page at 20,000 and 1,000,000 emails a month, before the one-month free trial on Foundation and Scale.
Works from your AI assistant, 25 of 100. 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 of 100. 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 of 100. 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 of 100. 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 of 100. 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 of 100. 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 of 100. 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?
What each one costs in 2026
Mailgun's pricing starts with a free plan of 100 emails a day. Basic is $15 for 10,000 emails a month, with $1.80 per 1,000 after that, so 20,000 emails come to $33. Scale is $700 for a million. Foundation and Scale both open with a free first month, which the prices here leave out.
Nitrosend's pricing is $20 for 20,000 emails on Pro and $500 for a million on Enterprise. Transactional, campaigns and flows draw on the same allowance, and contacts are unlimited.
At 20,000 emails a month, where most teams start, Nitrosend is $20 and Mailgun is $33. At a million, Nitrosend is $500 and Mailgun Scale is $700.
What sending costs at two volumes
List prices, USD, October 1, 2026| Scenario | Nitrosend | Mailgun |
|---|---|---|
| 20,000 emails a month | Pro, $20 a month | Basic, $33 a month ($15 plus 10,000 at $1.80 per 1,000) |
| 1,000,000 emails a month | Enterprise, $500 a month | Scale, $700 a month |
| Add newsletters and a welcome series | Counted in the same allowance, contacts unlimited | Mailing lists and templates, but no campaign builder or flows |
Dedicated IPs are available on Mailgun from 50,000 emails a month and included from 100,000. Nitrosend sells them from the Ultra plan. On Pro and above Nitrosend also accepts your own sending keys, Mailgun's included, so a team can keep Mailgun as the delivery layer and pay it directly.
Where Mailgun is the better pick
Mailgun scores higher on one of the seven tests, and it does a few jobs Nitrosend does not. For a pure sending workload they matter. Read these before you choose Nitrosend.
- Pick Mailgun if your application needs SMTP, inbound routes, validation or an SDK outside JavaScript. It has official SDKs for Go, Java, Node.js, PHP, Python and Ruby, an SMTP relay, inbound routes that receive, forward and store mail, and an email validation API. Nitrosend's SDK is Node and TypeScript, and other languages call its REST API. It has no SMTP relay, and it receives email only through an agent inbox that is still in beta.
- Pick Mailgun if a long record and deep sending controls matter most. It scores 9 to 4. Mailgun is one of the longest-running sending APIs, and Sinch bought it with Mailjet in 2021. Its plans list dedicated IP pools, automated dedicated IP warm-up, suppression management and a guaranteed uptime SLA. Nitrosend is a younger product from a small team.
Mailgun has an agent story too. Its official MCP server exposes more than 50 operations as tools, from sending and stats to templates, suppressions, routes and mailing lists, and it leaves out delete operations on purpose. It runs locally on your machine with a MAILGUN_API_KEY in the config, and Mailgun says it does not offer a hosted version.
The key is the part to check. Mailgun's MCP guide tells you to use a key scoped to the operations you need. Its API key guide lists what there is to scope with: account keys, which have complete access to the account, and domain sending keys, which can only post messages for one domain. Keys with narrower roles, such as read-only Analyst, are available on Enterprise and certain Business plans. A sending key is too narrow for the stats, suppression and template tools, so on other plans the key that runs the MCP server can usually do everything.
Mailing lists are the other thing to know. In Mailgun a mailing list is an email address, and a message sent to it is delivered to every subscribed member. The same send tool that sends one test email can therefore reach a whole list in one call, and Mailgun's own MCP guide warns that a crafted prompt can trigger operations you did not intend and tells you to review tool-call confirmations.
On Nitrosend the MCP server is hosted and signs in with OAuth, so no key sits in a config file. A campaign is created as a draft, approval is a separate call, and sending to all contacts also needs an explicit confirm_send_to_all. An OAuth session can read billing but cannot make a purchase, which stays with an account owner. An agent can create the account, send from a ready sender on a Nitrosend subdomain, and then run campaigns and flows from the same MCP server.
Moving from Mailgun to Nitrosend
There is no need to move delivery off Mailgun on day one.
- Keep Mailgun underneath. On Pro and above, connect your Mailgun key as the sending provider. Delivery stays on your Mailgun account, and the agent, flows and newsletters run in Nitrosend.
- Let the agent learn the brand. Ask the assistant to set up the Brand Kit from your website and it pulls in the colors, fonts and logo, so the first receipt already looks like yours. The transactional template guide covers what each receipt and reset needs.
- List your Mailgun templates before you move. Mailgun templates are written in Handlebars, with helpers such as if, each and equal, and they live either on one sending domain or on the account, separately in each region. Count them, note every helper and variable, and check each one against Nitrosend's template merge tags, which use the form {{ contact.first_name }}.
- Keep the streams apart. Nitrosend's guide to sending domains routes different mail through different subdomains, for example news.yourdomain.com for campaigns and txn.yourdomain.com for receipts, and its plans list stream separation for transactional and marketing mail, so a large promotional send cannot drag down receipts and password resets. The difference between transactional and marketing email is the background.
- Plan around the gaps. If your app relies on inbound routes, SMTP, email validation or a non-JavaScript library, keep Mailgun for that part. Nitrosend's agent inbox, which receives mail on your own domain, is in beta and enabled by request.
Which one to pick
Pick Nitrosend if an agent should set up, write, design and send the email from the assistant the team already uses, the same team also needs a welcome series and a newsletter, or nobody wants to build templates by hand. It scores higher overall, 86 to 67.5, and costs less at both 20,000 and 1,000,000 emails a month. Teams that want both can keep Mailgun for delivery and run Nitrosend on top. The Nitrosend MCP server and the ChatGPT app are the two ways most teams start, and transactional email is the primer on what belongs in which stream.
Pick Mailgun if the job is transactional email only, sent from application code in any of its SDK languages, and inbound routing, SMTP, validation and a long record matter more than anything else.
Nitrosend vs Mailgun FAQ
Yes. Mailgun's Free plan allows 100 emails a day with one sending domain and one inbound route. Foundation and Scale also start with a free month. Nitrosend's Free plan gives 8,000 emails up front and then 500 every month, with no expiry and no credit card.
Yes, at both volumes compared here. At 20,000 emails a month Nitrosend Pro is $20 against $33 on Mailgun Basic with overage. At a million, Nitrosend Enterprise is $500 against $700 on Mailgun Scale. Nitrosend's price also covers campaigns and automation flows, which Mailgun does not offer: its pricing FAQ says there is no send button in Mailgun.
Yes. Mailgun publishes an official MCP server for sending, stats, templates, suppressions, routes and mailing lists. It runs locally with a Mailgun API key, and Mailgun says there is no hosted version. Check which key you give it: Mailgun's account keys have complete access, and narrower role-based keys are on Enterprise and certain Business plans. Nitrosend's MCP server is hosted, signs in with OAuth, and also runs campaigns, flows, contacts and domains.
Add the Nitrosend MCP server at api.nitrosend.com/mcp as a connector in Claude and sign in with OAuth. Then ask in plain words. A transactional email goes out when the agent sends it; a campaign or flow is saved as a draft and goes out only after it is approved. The setup guide covers ChatGPT, Cursor and Codex too.
Yes. On Pro and above Nitrosend accepts your Mailgun key as the sending provider, so delivery stays on your Mailgun account while the agent, flows and newsletters run in Nitrosend.
This review does not score it, because neither product publishes a comparable inbox-placement number. Mailgun has the longer track record. Whichever you use, reputation belongs to the sending domain, so authenticate it and keep transactional and marketing mail on separate streams.