Nitrosend is the better choice than Instantly on four of the seven things this review compares: running email from an AI agent, being built for audiences who opted in, designed newsletters, flows and receipts in your own brand, and what the bill does as the list grows. Instantly is a cold outreach platform, built to send plain-text sequences to prospects from many connected mailboxes. Nitrosend is built for the email a business sends to its own customers and subscribers, and to be run by an agent from inside Claude, ChatGPT, Cursor or Codex. To send email from an AI agent with Nitrosend, add its MCP server (api.nitrosend.com/mcp) to Claude, ChatGPT, Cursor or Codex, sign in with OAuth, and describe the email: the agent drafts it in your brand, and a campaign or flow stays a draft until it is approved.
Nitrosend vs Instantly, compared
The quick version: five 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 Instantly, side by side
Checked September 25, 2026| Question | Nitrosend | Instantly |
|---|---|---|
| Send from the chatCan an agent send an email or sequence without anyone opening the web app? | Yes. Yes, through the MCP server. Campaigns and flows stay drafts until approved. | Yes. Yes, through its hosted MCP server once a person adds an API key. |
| Official MCP serverIs there a first-party MCP server an assistant can connect to? | Yes. Yes. A hosted server at api.nitrosend.com/mcp, with OAuth sign-in. | Yes. Yes. mcp.instantly.ai, with an API key. |
| Consent required by the termsDo the terms rule out emailing people who never opted in? | Yes. Yes. Unsolicited email and bought or scraped lists are not allowed. | No. No. It is built for cold outreach, within the law. |
| Newsletters and flowsCan it send designed newsletters and trigger-based flows? | Yes. Yes, on every plan including Free. | No. No. Plain-text sequences. |
| Contacts unlimitedAre stored contacts free on every plan? | Yes. Yes, on every plan. | No. No. 1,000 to 100,000 uploaded contacts by plan. |
Nitrosend meets 5 of 5 yes-or-no questions on this page, Instantly 2 of 5. 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 as every cold outreach comparison on this site. Each product gets a score out of 10 on each one, and the total adds each score times the points for that test. Nitrosend finishes ahead, 69 to 59.5, because each wins the tests that match its own job.
One test needs a plain explanation. "Built for opted-in audiences" scores whether a product is designed and licensed for email to people who asked to hear from you. It is not a judgment on cold email. In the United States, the FTC's CAN-SPAM guide asks for an accurate sender, a postal address and a clear way to opt out, not prior consent, and Instantly builds unsubscribe handling into every plan. It measures fit for a different job, and it does not help a reader whose job is cold outreach.
Each test, scored
Points out of 100, scores out of 10, September 25, 2026| What we compared | Points | Nitrosend | Instantly |
|---|---|---|---|
| Run from an AI agent | 20 | 9 out of 10 | 7 out of 10 |
| Built for opted-in audiences | 15 | 10 out of 10 | 2 out of 10 |
| Cold sending: mailboxes, warmup, rotation | 15 | 1 out of 10 | 10 out of 10 |
| Replies and prospect pipeline | 10 | 1 out of 10 | 10 out of 10 |
| Newsletters, flows and receipts, on brand | 15 | 10 out of 10 | 2 out of 10 |
| Cost as volume grows | 15 | 9 out of 10 | 5 out of 10 |
| Integrations, support, track record | 10 | 5 out of 10 | 7 out of 10 |
| Total score | 100 | 69 out of 100 | 59.5 out of 100 |
Where each one runs out
Rank 1Nitrosend
69 out of 100Total
- Priced by
- Emails sent
- Free plan
- 8,000 emails, then 500 a month
- Entry plan
- $20 a month, 20,000 emails
- Run from an AI agent9 out of 10Official MCP server with OAuth, API signup and a ready sender, so an agent sends with no dashboard (docs).
- Built for opted-in audiences10 out of 10Terms bar unsolicited email and purchased or scraped lists, and CRM imports come in unsubscribed by default (terms).
- Cold sending: mailboxes, warmup, rotation1 out of 10Sends from verified domains through its own delivery layer. It does not connect, warm or rotate Gmail mailboxes (docs).
- Replies and prospect pipeline1 out of 10Built to send, not to prospect, today. No reply inbox, stop-on-reply or lead pipeline for sequences yet; its Outreach feature is listed as coming soon (docs).
- Newsletters, flows and receipts, on brand10 out of 10Newsletters, trigger flows and receipts on every plan, drafted in a Brand Kit read from your own site (pricing).
- Cost as volume grows9 out of 10$20 for 20,000 emails and $100 for 125,000, with contacts unlimited and no add-ons to buy (pricing).
- Integrations, support, track record5 out of 10Shopify, Stripe, HubSpot, Attio and Mailchimp, five bring-your-own sending providers, a Node SDK, a CLI and signed webhooks for transactional email, but a young product from a small team (docs).
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 2Instantly
59.5 out of 100Total
- Priced by
- Emails sent and uploaded contacts
- Free plan
- None. A free trial
- Entry plan
- $47 a month, 5,000 emails, 1,000 contacts
- Run from an AI agent7 out of 10A hosted MCP server that covers the full API: accounts, campaigns, leads and analytics, authenticated with an API key (docs).
- Built for opted-in audiences2 out of 10Its credits plans sell a 450M+ B2B lead database for cold contact. Unsubscribe and bounce protection are built in (pricing).
- Cold sending: mailboxes, warmup, rotation10 out of 10Unlimited email accounts and unlimited warmup on every plan, with advanced warmup and rotation across mailboxes (pricing).
- Replies and prospect pipeline10 out of 10Unibox gathers replies from every mailbox, sequences stop on reply, and a CRM tracks each lead (pricing).
- Newsletters, flows and receipts, on brand2 out of 10Plain-text sequences to prospects. No designed newsletters, customer flows or receipts (pricing).
- Cost as volume grows5 out of 10$97 a month for 25,000 contacts, with lead credits a separate plan and mailboxes bought elsewhere (pricing).
- Integrations, support, track record7 out of 10API, webhooks and CRM integrations, premium live support from Hypergrowth, and a large outbound user base (pricing).
The verdict in short
Nitrosend leads 69 to 59.5 and wins four of the seven tests. Instantly is only better on three, and they are the three that make a cold program work. Mailboxes, because it connects unlimited email accounts, warms them and rotates sends across them. Replies, because Unibox collects every answer in one place, stops the sequence and passes the lead to its CRM. And integrations and support, because it plugs into the sales stack and adds premium live support from Hypergrowth. A team whose job is cold prospecting should pick Instantly.
At a glance
Nitrosend and Instantly are scored here on the same 7 tests, 100 points in all: Nitrosend 69 out of 100, Instantly 59.5 out of 100. Nitrosend takes its best score on Built for opted-in audiences and Newsletters, flows and receipts, on brand (10 out of 10) and its lowest on Replies and prospect pipeline (1 out of 10). Instantly takes its best score on Cold sending: mailboxes, warmup, rotation and Replies and prospect pipeline (10 out of 10) and its lowest on Newsletters, flows and receipts, on brand (2 out of 10). Instantly scores higher on Cold sending: mailboxes, warmup, rotation and Replies and prospect pipeline and Integrations, support, track record. Scores are unadjusted, and every Instantly figure was read on its own site on September 25, 2026.
How we scored
Two changes to the scoring on October 2, 2026 apply to all fourteen cold outreach comparisons on this site, not just this one. First, "Run from an AI agent" now carries 20 points, up from 15, and "Cold sending: mailboxes, warmup, rotation" carries 15, down from 20; the other five tests keep their weights. The site's stated view is that sending email is moving to AI agents: its transactional comparisons give the agent test 25 points and its marketing comparisons 20, and the cold outreach set was the only one below 20, so it now matches the marketing set. The five points come from the mailbox test because connecting, warming and rotating mailboxes is also sold on its own by infrastructure vendors such as Mailforge and Inframail, which these pages review on the same test, and it remains a 15-point test that cold outreach tools win outright. Second, the agent test is now scored on one written rule for every vendor: a first-party server the vendor runs and that can launch the send counts fully, one connected with a pasted API key or run on the user's own computer counts for a little less, and a third-party wrapper or a server that only drafts or reads counts for less again. On this page the two changes move Nitrosend from 65 to 69 and Instantly from 62.5 to 59.5.
Each test is a question with one answer per product, checked against that product's own pages and independent review sites on September 25, 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. Instantly prices are monthly list prices in US dollars, read on its own pricing page with monthly billing selected.
Run from an AI agent, 20 of 100. Can an agent inside Claude, ChatGPT, Cursor or Codex build the email or sequence, add the recipients, and send it, with no person opening the web app between the prompt and the send? An approval step completed through the agent's own tools counts as inside the agent. Moving into the web app to finish does not. 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.
Built for opted-in audiences, 15 of 100. Is the product designed and licensed for email to people who asked to hear from you, with consent recorded on every contact, unsubscribes honored automatically, and terms that rule out purchased or scraped lists?
Cold sending: mailboxes, warmup, rotation, 15 of 100. Can it connect many sending mailboxes, warm them up, and rotate a cold sequence across them so no single mailbox carries the volume?
Replies and prospect pipeline, 10 of 100. Does it bring replies from every sending mailbox into one inbox, stop a sequence when someone answers, and track each lead through to a booked meeting?
Newsletters, flows and receipts, on brand, 15 of 100. Can it send designed newsletters, automated flows such as welcome and win-back, and transactional email like receipts to your customers and subscribers, styled from your own site's brand?
Cost as volume grows, 15 of 100. What does the bill do as contacts and emails grow, at published list prices, once every add-on the job needs is counted: mailboxes, warmup, lead credits, contact caps and extra seats?
Integrations, support, track record, 10 of 100. How many tools does it plug into, what support comes with the plan, and how long has it been doing this at scale?
What each one costs in 2026
Instantly's pricing sets both an email allowance and an uploaded-contact cap on each plan. Growth is $47 a month for 5,000 emails and 1,000 contacts. Hypergrowth is $97 for 25,000 contacts, with its plan card listing 125,000 emails a month and its comparison table 100,000. Light Speed is $358 for 500,000 emails and 100,000 contacts. The lead database is a separate subscription, Instantly Credits, from $47 a month, and the mailboxes you send from are connected from your own email provider.
Nitrosend's pricing charges for emails sent, not for contacts: $20 for 20,000 emails on Pro, $100 for 125,000 on Ultra, and $300 for 500,000 on Enterprise. Newsletters, flows and receipts draw on the same allowance, and a contact who never gets emailed costs nothing to keep.
What sending costs as the list grows
List prices, USD, September 25, 2026| Scenario | Nitrosend | Instantly |
|---|---|---|
| Entry plan | Pro, $20 a month (20,000 emails, contacts unlimited) | Growth, $47 a month (5,000 emails, 1,000 contacts) |
| About 100,000 emails a month | Ultra, $100 a month (125,000 emails) | Hypergrowth, $97 a month (25,000 contacts) |
| About 500,000 emails a month | Enterprise, $300 a month (500,000 emails) | Light Speed, $358 a month (100,000 contacts) |
| Sending mailboxes | Not needed. Nitrosend sends from your verified domain | Unlimited mailboxes connected from your own email provider |
| Lead data | Not offered. You bring contacts who opted in | Instantly Credits, from $47 a month, 450M+ B2B leads |
The headline prices are close at 100,000 emails a month. The difference is what each price leaves out. A cold program on Instantly also pays for its mailboxes and, usually, lead data. A customer list on Nitrosend has no contact cap to outgrow.
Where Instantly is the better pick
Instantly takes three of the seven tests, worth 35 points between them, and they are the core of cold outreach. Each line below is from Instantly's pricing page.
- Mailboxes, warmup and rotation. Unlimited connected email accounts and unlimited warmup on every plan, with sends spread across mailboxes so no single one carries the volume. Nitrosend sends from verified domains through its own delivery layer and does not connect or warm Gmail or Outlook mailboxes.
- Replies and pipeline. Unibox brings replies from every mailbox into one place, a reply stops the sequence, and its CRM tracks the lead from there. Nitrosend has no reply inbox for sequences. An agent inbox that receives mail on your own domain is in beta.
- Integrations and support. API, webhooks and CRM integrations, and premium live support from Hypergrowth. Nitrosend is a younger product from a small team, with a handful of data connectors.
Instantly's agent story is strong too. It hosts an MCP server at mcp.instantly.ai that exposes every endpoint of its API as a tool, from email accounts and campaigns to leads and analytics, authenticated with an API key. That raises the question that matters most when an agent runs sending: where does a draft stop and a live send start? On Instantly the line is the key. Each API key is created with scopes chosen at setup, and starting a campaign needs a campaign update scope. Read together, those two pages suggest that a key made without it lets an agent build a campaign and load leads but not start it, though Instantly does not document that setup as a safeguard. On Nitrosend the line is in the product: a campaign or flow stays a draft until it is approved, while a single transactional email sends on the call. Nitrosend's server signs in with OAuth, and an agent can create the account and send with no mailbox or DNS set up first.
Until its Outreach feature, listed in its docs as coming soon, launches, Nitrosend is the wrong tool for cold prospecting, and its terms say so: no unsolicited bulk email, no messages to people who have not opted in, and no purchased, rented or scraped lists. That is the norm for permission-based senders, not a quirk. Postmark's terms, for example, require every list to be a permission-based subscription and prohibit lists bought or rented from a third party. The practical risk is an agent asked to "email these 200 leads" through whatever send tool it has, which on a permission-based service breaks the terms and puts the account at risk.
Instantly is built for cold prospecting across many mailboxes, and Nitrosend's own Outreach feature is still listed as coming soon. George Hartley, Nitrosend's co-founder, has said what he thinks of careless outbound. On The Breakout CEO in August 2026 he said of AI outbound: "outbound where you finding leads, you know, it's that horrible spray and pray, you know, it's like, uh, it reflects badly on your brand." On SaaS Stories in September 2026 he said: "You can't run outbound through a bulk system because that's immediately going to cook everything like Gmail will just cut you off." Until Nitrosend's Outreach ships, Instantly is the one built for this job.
Using Instantly and Nitrosend together
The two fit together, one for each job.
- Keep cold on Instantly, on its own domains. Cold infrastructure and email to customers need different domains, different mailboxes and different deliverability rules. Instantly's own guide to secondary domains gives the reason: complaints and bounces on a cold domain can lead to blacklisting, which "could create problems for normal business operations like sending updates to existing clients/customers". Keep the domain your customers know for the email they asked for.
- Move the people who say yes. When a prospect becomes a customer or subscribes, they belong on your own list. Nitrosend's terms rule out emailing people who never opted in, and its CRM imports come in unsubscribed by default, so a contact joins your sendable audience only once they have agreed.
- A reply is not a subscription. A prospect who answers a cold sequence has agreed to a conversation, not to a newsletter. Under the GDPR, consent must be "specific, informed and unambiguous", given by a statement or a clear affirmative action. Ask them to sign up, and import them once they have, so the consent on the contact record is real.
- Hand the list to the agent. Describe the welcome series or the next newsletter in the chat, and Brand Kit applies your logo, colors, fonts and voice. The format is the other way round from cold. Instantly's delivery optimization setting strips all HTML and sends plain text because "spam filters are more likely to flag HTML emails", and turning it on switches off open tracking. A list that asked to hear from a brand is the opposite job, and a designed newsletter in the brand's own look is what it calls for. The newsletter guide covers the format.
Which one to pick
Pick Nitrosend if you email customers and subscribers who opted in, and you want an AI agent to run it: the newsletter, the welcome and win-back flows, and the receipts, in your brand's own design, with contacts free on every plan. The Nitrosend MCP server and the email marketing guide are the places to start.
Pick Instantly if your job is cold prospecting: sending sequences to people who have not heard from you yet, across many mailboxes, and working the replies into meetings. It is built for that today, and Nitrosend is not: its own Outreach feature is still listed as coming soon. The email marketing laws guide covers what each kind of sending needs to stay compliant.
Nitrosend vs Instantly FAQ
Nitrosend, by 69 to 59.5 on the seven tests. Nitrosend wins running email from an AI agent, being built for opted-in audiences, newsletters, flows and receipts, and cost as the list grows. Instantly wins mailboxes, replies and integrations, the three that decide a cold program.
Not yet. Nitrosend's docs list an Outreach feature, for finding leads and sending them sequences, as coming soon. Until it launches, Nitrosend sends to people who opted in, and its terms rule out unsolicited bulk email and purchased or scraped lists. Cold outreach today belongs on a dedicated tool such as Instantly, on domains kept apart from the one your customers know.
In the United States, yes, within CAN-SPAM, which requires an accurate sender, a postal address and a clear way to opt out, honored within 10 business days. Rules differ by country. This review scores fit for an opted-in audience, not legality.
Yes. Instantly hosts one at mcp.instantly.ai that covers its full API, authenticated with an API key. Nitrosend's MCP server signs in with OAuth.
Add Nitrosend as a connector in Claude (it is in the Claude directory), or add the MCP server at api.nitrosend.com/mcp in ChatGPT, Cursor or Codex, and sign in with OAuth. Then ask for the email in plain words. The agent drafts it in your Brand Kit, can send you a test, and the campaign stays a draft until it is approved. The MCP page has the setup.
Yes. Each plan caps uploaded contacts, from 1,000 on Growth to 100,000 on Light Speed. Nitrosend has unlimited contacts on every plan and charges for emails sent.
Yes, and it is a common setup. Instantly handles cold prospecting on its own domains and mailboxes, and Nitrosend handles email to the customers and subscribers who opted in.