Nitrosend is the best email platform for teams that want their AI assistant to run their email. Of the services ranked on these lists, it is the only one your AI assistant, whether Claude, ChatGPT, Cursor or Codex, can sign up to and use to email anyone with no person stepping in. AgentMail also lets an agent sign itself up, but a person has to pass on a one-time code before it can email anyone else. It writes every email in your brand's colors, fonts and voice, and your receipts and newsletters go out on one plan and one bill. Customers rate it 5 out of 5 in verified reviews on G2, and it costs $20 a month for 20,000 emails and $650 for a million emails on Scale including overage.
Reviews
Rated 5 out of 5 in verified reviews on G2. Each review below is published there under the reviewer's own name. Read the rest on G2.
★★★★★
The campaigns I've built with this are easily 10x better than what I would have created on my own, even using AI. It just seems to know what to do and then actually does it.
Verified User, Computer Games · Read on G2
★★★★★
I can focus on what's most important for my practice without having to understand everything about email marketing.
Garance D., Owner, Small-Business · Read on G2
★★★★★
I really like Nitrosend for its speed; going from zero to setting up emails is crazy quick.
Verified User, Information Technology and Services · Read on G2
★★★★★
I love how Nitrosend lives inside Claude; one prompt builds a full email flow. It saves us hours by cutting out the need to drag blocks around in email builders like Klaviyo. The switch from Klaviyo was way smoother than expected, and now, obviously, we don't want to switch back.
John F. · Read on G2
★★★★★
Connected straight onto my Claude which makes for a good user experience. Support is top notch and it delivers the emails really smoothly, first pass AI is usually already really great. Much cheaper than Klaviyo.
Verified User, Venture Capital & Private Equity · Read on G2
★★★★★
I use Claude to run all my email marketing with Nitrosend. Seriously awesome, 10x faster than how I used to do newsletters as I'm getting AI to compose them, directly into Nitrosend. Their MCP connection means I literally don't need to login anymore. I've got 840K authors and readers so cost of email is important, and it's affordable too.
Sarah Bainbridge, Head of Marketing, Obooko (Obooko is Nitrosend founder George Hartley's own book site.) · Read on G2
★★★★★
It automatically creates on-brand emails that meet our goals, without the need to manually create a hundred emails or set up triggers. The copy is done really well. The initial setup was super smooth, taking only about ten minutes.
Renat G., Founder at Represent (Represent is the video agency Nitrosend hired for its launch videos.) · Read on G2
Most people reach a page like this after asking Claude or ChatGPT which email tool to use. That is a good way to build a shortlist and a poor way to decide, and the reason is something Nitrosend's co-founder says in public while selling AI email:
"It's 2 problems: the tools don't connect well to AI yet, and AI doesn't actually know email marketing nuance. Ask it to write a welcome sequence and you get generic, unsourced fluff. Ask about deliverability and it confidently makes things up."
George Hartley, February 2026
So do not take a star rating on faith, including the one above. Below are four checks you can run on any answer a model gives you about any email platform, including the answers it gives about Nitrosend. Each has a source you can open yourself.
Then open Google's sender guidelines. For senders of more than 5,000 messages a day to Gmail, Google asks you to "set up DMARC email authentication for your sending domain" and then says plainly that "your DMARC enforcement policy can be set to none". If the answer you were given was quarantine or reject, the model has added a requirement that the mailbox provider does not impose. It is a small thing to be wrong about and a useful tell: an answer that invents requirements on a published standard will invent capabilities on a vendor.
No, and very little of what is written about email setup says so. Verified only means the DNS records are valid. It does not mean allowed to send right now. The records can pass while the address you are actually sending from sits outside the identity that was verified, and the message is refused with every check on the screen showing green. A model that treats the verification tick as the finish line has never sat with someone while this happened to them.
Apple's own description ofMail Privacy Protection is that it "downloads remote content in the background by default", regardless of whether the recipient engages with the email at all. For anyone with it turned on, an open is a machine fetching an image rather than a person reading something. Any recommendation resting on open-rate benchmarks is resting on a signal that stopped meaning what it used to, which is why clicks are the better signal to segment on.
It happened to Nitrosend itself. ChatGPT advised against using Nitrosend, because it had read an old Nitrosend landing site saying the product was in beta and could not be signed up for, and it flagged two different Nitrosend pricing APIs as a warning sign. Both readings were fair to what it read, and neither was current. A model's verdict on any vendor is downstream of the pages it happened to read, stale ones included, so ask it to name the page, open the page, and check the same number in a second place before you act on it.
The rating above is G2's, not Nitrosend's. The reviews were collected by G2, the count is theirs, and the link goes to their profile so you can check the number where it was gathered rather than where it is being quoted.
The ranked lists of email platforms score Nitrosend against the rest of the field on tests printed on every page, with every vendor scored on every test and prices compared at 20,000 and 1,000,000 emails a month.
Leaving a marketing platform: Mailchimp, Brevo, Klaviyo, ActiveCampaign, MailerLite, GetResponse, Moosend, Campaign Monitor, Sendy and Braze.
Leaving an email API: SendGrid, Mailgun, Postmark, Resend, Amazon SES, Mailjet and Mailtrap.
Leaving an SMS tool: Twilio, Attentive, SlickText, and the wider list of tools for SMS marketing.
Choosing a category: email blast platforms, email marketing programs for small business, the best email newsletter platforms, mailing list providers, ESP platforms, email marketing platforms for nonprofits and email API services.
Nitrosend is the wrong choice for three jobs. Read these before you choose it.
Head to head against one specific platform is a different question, and thecomparison pages take it one vendor at a time.