Sort Cold Email Replies With an AI Agent, Instantly and Make

The short answer: while one person can read every reply the day it arrives, Instantly's own tagging and a twice-daily pass do this job: Interested, Not interested and Out of Office are on by default at no extra charge, per the custom labels article. Once that stops being true, put a Make agent behind Instantly's webhooks: it files each reply as interested, not now, unsubscribe or out of office, blocklists every request to stop, and hands interested replies to a person with a draft. The webhooks and custom labels need Hypergrowth, $97 a month on monthly billing on the pricing page, checked on 26 October 2026. For example, at 5 Make credits a reply, 150 replies use 750 of the Free plan's 1,000 credits a month (Make pricing), and at 2 minutes of reading and filing per reply the agent takes over 150 x 2 = 300 minutes a month.

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The four buckets run on different clocks. An interested reply cools by the hour. A not-now carries a date someone has to keep. An out-of-office is noise with a return date inside it. And a request to stop is a duty, not a preference: under GDPR Article 21(3), once a person objects to direct marketing, their data may no longer be processed for it (GDPR). Sorting is the cheap part. Acting on each bucket the same day is what slips.

Before you build:

1. The credit sum. Make counts one operation for the trigger and one each time a module handles a bundle (operations guide), and its AI Provider bills tokens in credits too: on the Small tier one credit covers 18,080 input and 2,260 output tokens (credits). For example, a trigger, the agent and two action modules make 4 operations; assuming a short reply fits in one credit of tokens, that is 5 credits a reply.
2. The plan you already send from. Instantly sends webhooks from Hyper Growth up, per its webhooks article, and Make's Instantly app asks for an API key from a Hypergrowth plan or above (Make's Instantly app). On Smartlead, Pro is the first plan with API and webhooks, per its pricing file.
3. Your rules, written down, with real replies. Two sentences per bucket and three replies from last month for each. They become the label descriptions in Instantly and the agent's instructions in Make.
4. Two baselines. The median hours from reply to first answer on interested replies over the last four weeks, and the number of people who asked to stop and still received a step. The second should already be zero. Count it anyway.

How a reply moves through the system

1. Instantly tags it. In Settings, Preferences, AI Automations, switch on "Automatically tag lead status in replies". Add two custom labels, Not now and Unsubscribe request, with descriptions taken from your rules, and paste sample replies into the Test AI tab before going live, as the custom labels article suggests. The tags sort Unibox for the reps; the agent's bucket drives the actions, and the weekly check reads replies where they disagree.
2. The webhook fires. Under Integrations, Webhooks, Add Webhook, point the Reply received event at the URL of a custom webhook in Make (Instantly webhooks, Make Webhooks app). The payload carries the full reply text, the subject, the lead's email and a unibox_url link to the conversation, per the event reference. Auto-replies arrive as their own event type, auto_reply_received, so subscribe to it too and route it straight to the out-of-office branch.
3. The agent decides and drafts. Add Make AI Agent (New), Run an agent (agent guide). Instructions: your four buckets plus a fifth, unclear. Input: the reply text and subject. Response format: Data structure, with fields for the bucket, any date the person named, and a draft for interested replies only. Give it no tools: it reads and writes text, nothing else. Make lists the app as an open beta whose functionality and pricing may change (app reference).
4. A router gives each bucket its own route (router):
   • Unsubscribe: Instantly's Add Entries to the Blocklist module runs at once (Make's Instantly app), and a row goes to the log. This is the one route that acts without a person, because its action stops email instead of sending it.
   • Out of office: the return date goes to the log, so whoever owns the lead can hold the next touch until then.
   • Not now: the date and the person's own words go to a Google Sheets row for someone to carry into the CRM.
   • Interested: a Slack message to the reps' channel with the draft and the Unibox link.
   • Unclear: Slack again, with no draft.
5. A person answers. The rep opens the conversation from the link, edits the draft and sends it from Unibox. Nothing the agent writes reaches a prospect without that click. A scenario that starts with an instant trigger is switched off at its first error (scenario settings), so set up the error handling in how to use Make.

If you send from Smartlead

Smartlead sorts replies itself from Pro. In a campaign's settings, under General, switch on Intelligent AI Lead Categorization and pick the categories the AI may assign, up to 5 on Pro, per its categorisation article. The defaults include Interested, Not Interested and Do Not Contact (lead concepts). Add Out of Office and Not now as custom categories (lead categories), and those five fill Pro's allowance exactly.

Categories can also start subsequences inside Smartlead, so not-now leads can drip back without an outside tool. For drafts, register a webhook on LEAD_CATEGORY_UPDATED, whose payload carries the category, the lead and the last reply (webhook guide), send it to the same Make custom webhook, and let the agent draft only when the category is Interested. Campaign setup on that side is in how to use Smartlead.

The free version: a routine, not a tool

Instantly's built-in tags need no upgrade; the custom labels article restricts only custom labels to Hyper Growth and Light Speed. On Growth, $47 a month on the pricing page when checked on 26 October 2026, the Unibox is preview-only, per the pricing file, so you answer from the mailbox itself.

Twice a day: answer the Interested folder from the mailbox. Read Not interested for "not now" wording and for requests to stop, and blocklist the second group by hand. Copy return dates from Out of Office into a sheet. The blocklist trigger for leads who click unsubscribe carries no plan requirement, while status and phrase triggers need Hyper Growth (AI Blocklist Triggers). On Smartlead Base, AI categorisation is not available at all (categorisation article), so the same routine runs in the master inbox.

That routine is enough on its own, until replies start waiting overnight.

What the paid pieces add

Hypergrowth adds custom labels, blocklist phrase triggers, webhooks and replies inside Unibox (pricing file). Make adds what labels lack: a next step per bucket, dates pulled from the text, drafts and a log. Phrase triggers catch replies that contain the words you listed, such as "unsubscribe" or "remove me". The agent also catches "please stop writing to me".

Instantly's own AI Reply Agent drafts replies in Human-in-the-loop mode and waits for your approval; Autopilot needs Hyper Growth or above (AI Reply Agent). It costs 5 credits per reply on the separate Credits subscription, which starts at $9 a month for 150 credits in the pricing file, checked on 26 October 2026: for example, 150 / 5 = 30 drafts a month at that tier.

Those credits are charged when a draft is generated, whether anyone sends it, edits it or deletes it, and the same article suggests moving from approval to Autopilot once you are comfortable. A meter that runs per draft pays the vendor the same for a reply you throw away, so set the agent's monthly credit budget before switching anything on.

The monthly bill, side by side

Every figure above was checked on 26 October 2026. Make's page names its paid plans and says yearly prepayment costs less than monthly billing, but draws the prices in the browser behind a bot check, so read them there before you outgrow the Free plan.

How to know it worked

• Accuracy. Each week, someone labels 30 replies without seeing the agent's bucket, then compares. Count the misses per bucket. A missed request to stop matters more than a misfiled not-now, so read that column first.
• Speed. Median hours from reply to first answer on interested replies, against the four-week baseline.
• Safety. People who asked to stop and still received a step: zero, every week.
• Holdout. Run the scenario on one campaign and a comparable one on the manual routine for four weeks. Compare response time and meetings booked per 100 interested replies. If the two campaigns book at the same rate, the agent is buying you hours, not meetings, and that is worth knowing before you add volume.

Comparing the two senders first? Smartlead vs Instantly sets their plans side by side.

FAQ

Does the agent ever send anything itself?

No. It has no tools, so all it can do is return text to Make. The only automatic action in the scenario is the blocklist entry, and that stops email rather than sending it.

Why not rely on Instantly's labels alone?

If someone reads every reply the same day, do. Labels sort, but they do not pull a return date out of an auto-reply, draft an answer or keep a log, and phrase triggers match only the text you list (AI Blocklist Triggers).

What about replies in other languages?

Instantly's tagging works in more than 50 languages, per the custom labels article. Give the agent one sample reply for each language you receive, and keep unclear as its exit for anything it cannot read. Mailboxes and sending limits on the Instantly side are in how to use Instantly.