# Best AI agents for follow-up emails in 2026

> Which AI follow-up agent fits depends on who you’re emailing: prospects, your own users or your inbox. Tools by category, with prices checked October 10, 2026.

Source: https://behavly.io/compare/best-ai-agents-for-follow-up-emails · Updated October 10, 2026 · Competitor details checked October 10, 2026 on each vendor’s own site

The best AI agent for follow-up emails depends on who you’re following up with: cold prospects, your product’s users, or your own email threads.

- **Instantly**: best for cold-email teams that want one agent to answer replies and chase people who don’t reply.
- **HubSpot Prospecting Agent**: best for HubSpot teams that want signal-based outreach sent from each rep’s own inbox.
- **lemlist**: best for small outbound teams that want AI to draft the whole sequence, then approve it before launch.
- **Artisan**: best for funded B2B teams that want an AI BDR to prospect, follow up and handle replies.
- **Behavly**: best for following up with your own users, with each email written from what that person did in your product.
- **Superhuman**: best for making sure your own sent emails don’t go unanswered.
- **Gmail Nudges and Gemini**: best free option, with reminders for unanswered mail and help drafting the reply.
- **Lindy**: best for handing your own meeting and inbox follow-ups to an assistant.
- **Zapier Agents**: best for wiring a custom follow-up to a form, CRM or inbox trigger.

Not sure which kind you need? Start with [what an AI follow-up agent is](https://behavly.io/guides/ai-follow-up-agent), then use the categories below.

#### How we picked

Most lists that rank for this question are written by a vendor, and each one puts its own product first. This one is written by a vendor too. Behavly is our product, so it gets the same strengths and gaps as every other tool here, including what it isn’t for.

We started from the tools that search results and AI answers name most often for this question. Then we added the product follow-up tools those lists mostly miss. For each one, we checked five things on the vendor’s own pages:

- **What the agent does**: decides when to follow up, writes the email, sends it, or some mix of the three.
- **What triggers a follow-up**: silence after a sales email, a buying signal, something a user did in your product, or a thread you started.
- **Approval**: whether you can read each email before it sends, and what the default is.
- **Where it sends from**: your own mailbox, a rep’s connected inbox, or mailboxes the vendor sets up for you.
- **Price**: the lowest plan that includes the agent, and what it’s metered on.

Prices were read from each vendor’s own pricing page on October 10, 2026, in US dollars. Where a page contradicted itself, or we couldn’t confirm a detail, we left it out. Prices change often, so check before you buy.

#### AI follow-up agents compared

| Tool | Category | What triggers a follow-up | Sends from | Approval | Starts at |
| --- | --- | --- | --- | --- | --- |
| Instantly | Cold outreach | No reply, a new reply, or a “No Show” label | Mailboxes you connect | Approve each reply, or Autopilot on Hypergrowth and above | $47/month; Reply Agent listed in the $194 bundle |
| HubSpot Prospecting Agent | Cold outreach | Buying signals and sequence steps | The contact owner’s connected inbox | Review before sending, or send automatically | Sales Hub Starter, plus $1 per lead |
| lemlist | Cold outreach | No reply after a sequence delay | Senders you connect | You approve the campaign before launch | $55/month billed yearly ($69 monthly) |
| Outreach | Cold outreach | Agent sourcing rules and sequences | The prospect or account owner’s mailbox | Optional manual first step | Not published |
| Artisan | Cold outreach | Campaign cadence, buying signals and replies | Your domains, in reps’ names | Optional; autonomous by default | $250/month billed yearly |
| Behavly | Product follow-ups | What a signed-in user did, or didn’t do, in your product | Your own mailbox | Optional hold on an Agent, off by default | Free; Agents from $79/month |
| Superhuman | Personal inbox | No reply by the reminder time | Your Gmail or Outlook account | You send every draft | $25 per member billed yearly |
| Gmail Nudges and Gemini | Personal inbox | Unanswered sent mail; you ask for each draft | Your Gmail account | You send everything | Free |
| Lindy | Agent builder | A meeting ending, a schedule or your request | Inboxes you connect | Sending waits for approval, per its pricing FAQ | 7 days free with $50 in credits |
| Zapier Agents | Agent builder | An app event, a schedule, or on demand | The email app you connect | Optional, set in the agent’s instructions | Free (400 activities a month) |

#### Following up with prospects (cold outreach)

These agents follow up with people who don’t know you yet, or haven’t replied. The usual trigger is silence: no reply after a set number of days. Most also read replies, and some book meetings. They work from contact lists, public data and buying signals such as funding or job changes.

##### Instantly

Instantly’s **AI Reply Agent** reads each prospect’s reply, then drafts and sends a response. With follow-ups on, it also emails leads who don’t reply. A No-Show Recovery mode chases leads marked “No Show,” and with Calendly connected it can book meetings.

- **Where it’s strong**: Replies, no-reply follow-ups and no-show rebooking in one agent. Approve each reply (Human-in-the-Loop) or let it run on Autopilot. A free trial with 100 credits and no credit card.
- **Where it falls short**: Built for cold email only. Autopilot needs Hypergrowth or above, and each reply costs 5 credits. Some figures on the pricing page don’t match, so confirm your plan with Instantly.
- **Pricing**: Outreach plans from $47/month billed monthly (5,000 emails). The pricing page lists the AI Reply Agent in its Scale bundle, at $194/month billed monthly or $175 yearly.

##### HubSpot Prospecting Agent

HubSpot’s **Prospecting Agent** watches for buying signals such as funding, leadership changes and site visits, then researches the account and drafts outreach. Sequence mode follows the steps and delays you set. Adaptive mode adjusts to engagement, within your limits on gaps and emails per person.

- **Where it’s strong**: Sends from the contact owner’s connected inbox, so replies reach the rep. Choose **Review before sending** or **Send automatically**. Everything stays in your CRM.
- **Where it falls short**: Metered per lead on top of seats, and Sales Hub Professional adds a required $1,500 onboarding fee. The free CRM doesn’t include the agent.
- **Pricing**: $1 for each lead the agent recommends outreach for, paid in HubSpot Credits. Sales Hub Starter was listed from $7 per seat a month billed yearly, with $20 struck through. Professional is $90 per seat a month billed yearly.

##### lemlist

lemlist’s **lemAgent** builds a whole campaign from a conversation: the list, steps, timing, branching and every message. Nothing launches until you approve it. Follow-ups then go only to people who haven’t replied, and a reply typically stops the sequence.

- **Where it’s strong**: A clear approval gate before anything sends. The AI drafts the full sequence, not just one email. Unlimited users on the Email plan. A 14-day free trial with no credit card.
- **Where it falls short**: After launch, follow-ups run as fixed sequence steps. Built for cold outreach. No free plan, and Multichannel is priced per user.
- **Pricing**: Email plan $69/month billed monthly, or $55 yearly, for 50,000 emails a month. Multichannel $109 per user a month billed monthly, or $87 yearly.

##### Outreach

Outreach’s **Revenue Agent** finds and enriches accounts, then adds prospects to a sequence it writes for. Outreach says plays can run fully on their own, with agents sending on the seller’s behalf. A Reply Agent, for objections and questions, is listed as coming soon.

- **Where it’s strong**: Sends from the prospect owner’s mailbox by default. Enterprise controls such as exclusive sequences and daily limits. The Revenue Agent is included in the Amplify package.
- **Where it falls short**: No published prices, and the reply agent hasn’t shipped. To review AI emails, Outreach suggests making the first step a manual email.
- **Pricing**: Per user, plus AI credits, from Amplify Essentials (10,000 credits) to Pro (100,000). Prices are on request.

##### Artisan

Artisan’s AI BDR, **Ava**, finds leads, writes and sends outreach, handles replies and objections, and books meetings. Besides cold and warm outbound, a cross-sell and upsell mode emails existing users, working from CRM data and webhooks.

- **Where it’s strong**: One agent covers the whole loop, replies included. It sends in your reps’ names from your own domains. You can require approval and lock the tone and calls to action.
- **Where it falls short**: Autonomous by default. A high entry price, billed yearly, and team pricing isn’t public. The existing-user mode needs the Employee plan or higher.
- **Pricing**: A free plan (300 credits a month) covers leads and enrichment, not campaigns. Intern is $250/month billed yearly, about 500 leads contacted a month. Employee is $600/month billed yearly.

##### Others in this category

- **11x (Alice)**: email and phone sequences with reply handling, sent from mailboxes 11x manages. Priced per lead, on yearly contracts.
- **AiSDR**: month-to-month from $250 a month. It buys and sets up the mailboxes and domains for you.
- **Apollo**: a free plan, and an AI Assistant, labeled introductory, that drafts follow-ups and builds sequences for you to confirm.

#### Following up with your own users (product follow-ups)

Here the person already signed up. The follow-up is about what they did or didn’t do in your product: never invited a teammate, tried a feature once, went quiet. That needs activity tied to a signed-in person, which cold-outreach tools don’t have.

##### Behavly

Behavly, our product, is an AI agent for SaaS teams. A tracking script in your signed-in app records what each person does. You describe a follow-up path in words, and Behavly lays out the emails, waits and branches. When someone reaches an email step, Behavly writes that email from their own activity.

People enter as they qualify, and emails go out from your own mailbox inside your sending window. A reply ends the path by default and lands in Behavly’s inbox, next to that person’s activity.

- **Where it’s strong**: Two people at the same step get different emails, each about what they did. Branches can use logins, opens, clicks, replies, page visits and actions in your product. **Skip if they already did it** drops an email whose job is done. **Preview** writes any step for a real person without sending it. Emails can be written in each recipient’s language.
- **Where it falls short**: Not for cold outreach or bought lists: it writes to people who signed up for your product or filled in your forms. Email only, with no SMS or LinkedIn steps. Your own mailbox suits one-to-one volume, not bulk sends. It needs the tracking snippet on your signed-in product. Few integrations (no native Stripe, Segment, HubSpot or Zapier), though it has an MCP server and an API. Agents need Starter or above. On an Agent, approval is off until you turn on **Hold Behavly-written emails for approval**.
- **Pricing**: Free: 100 tracked contacts and 50 AI-written emails a month, without Agents. Starter $79/month (one Agent, 2,000 AI emails). Growth $249/month (five Agents, 8,000). Scale $699/month (unlimited Agents, 30,000), through sales.

##### HubSpot Nurture Agent (beta)

HubSpot’s **Nurture Agent**, in beta, rewrites automated marketing emails for each contact: the subject line, preview text, call to action and body. It does this for a share of recipients, 50% by default, using CRM data and web research.

- **Where it’s strong**: Per-contact writing inside workflows you already run, for up to 20,000 runs a month.
- **Where it falls short**: Still in beta. It writes from CRM data and web research, so it’s only as specific as your CRM. It rewrites a share of recipients, not everyone.
- **Pricing**: Needs Marketing Hub Professional or Enterprise, plus HubSpot Credits.

##### Customer.io, Bento and Sequenzy

These lifecycle tools also follow up with your users on product or billing events. Their pages describe AI that builds the flow and its templates, not each person’s email at send time. Customer.io’s agent builds automations as drafts. Bento’s Tanuki drafts flows and copy. Sequenzy turns a goal into a full sequence.

Customer.io starts at $100 a month, Bento at $29, and Sequenzy has a free plan. For what each one’s AI writes, see [best AI email tools for SaaS](https://behavly.io/compare/best-ai-email-tools-for-saas).

#### Following up on your own threads (personal inbox)

If the follow-up you mean is “I sent an email and heard nothing,” you don’t need an outbound agent. These tools live in your own inbox. They spot unanswered threads and help you write the nudge, and you press send.

##### Superhuman

Superhuman’s **Auto Reminders** bring back emails that haven’t had a reply, and its AI judges from your last message whether a follow-up is needed. Its **Auto Drafts** feature writes that follow-up about an hour before the reminder returns. It runs on your Gmail or Outlook account.

- **Where it’s strong**: It picks out which sent emails actually need a follow-up. Drafts sit with your other drafts, and nothing leaves until you send it.
- **Where it falls short**: One person’s inbox, with no sequences or bulk sends. AI drafts need the Business plan, and no auto-send setting is documented.
- **Pricing**: Starter $25 per member a month billed yearly ($30 monthly), with Auto Reminders. Business $33 billed yearly ($40 monthly), with Auto Drafts.

##### Gmail Nudges and Gemini

Gmail’s **Nudges** setting lists sent emails you may need to follow up on. Gemini’s **Help me write** drafts or polishes the reply, and since May 2026 it can pull context from Gmail and Drive. You ask for each draft and send it yourself.

- **Where it’s strong**: Free and already in your inbox. Google says Help me write is rolling out to everyone at no cost.
- **Where it falls short**: No automatic drafts or sending. Nudges need conversation view, and some features reach US English users first.
- **Pricing**: Free in Gmail. Google Workspace business plans also include Gemini in Gmail.

#### Building your own follow-up agent

Agent builders let you wire a follow-up to any trigger: a new email, a form, a schedule, a meeting ending. They’re flexible, but you design the logic, the prompts and the safety checks yourself.

##### Lindy

Lindy is an AI assistant for your inbox, calendar and meetings. It drafts replies in your voice, and its meeting follow-up skill writes a recap when a meeting ends. It sends through the inboxes you connect, two to five depending on plan.

- **Where it’s strong**: Inbox, calendar and meeting follow-ups in one place. Its pricing FAQ says sending an email waits for your approval.
- **Where it falls short**: No sequence logic or deliverability tools for sending at volume. Usage is metered in credits, so heavy use costs more.
- **Pricing**: Free for 7 days with $50 in credits, no card. Paid plans are priced in credits per active user, and top-ups cost $10 per 1,000 credits.

##### Zapier Agents

Zapier Agents take actions across Zapier’s app catalog, so a follow-up means giving the agent an email action, such as your Gmail. It can run on demand, on a schedule, from a Zap, or when an app event happens, like a new email arriving.

- **Where it’s strong**: Triggers from thousands of apps, sending through your own accounts. You can tell it to ask before acting, or add a human-in-the-loop step in a Zap. A free tier.
- **Where it falls short**: You design the logic yourself. Zapier is moving Agents into AI by Zapier, where each agent becomes a Zap with one AI step. After the move, approval before a tool runs is off by default.
- **Pricing**: Agents Free includes 400 activities a month. Agents Pro is $400 billed yearly, about $33 a month, for 1,500 activities.

#### How to choose

| If you want to | Start with |
| --- | --- |
| Follow up with cold prospects at volume, on a small budget | Instantly or lemlist |
| Follow up from reps’ own inboxes, inside HubSpot | HubSpot Prospecting Agent |
| Hand outbound to an AI, from first email to booked meeting | Artisan or 11x, or Outreach if you already use it |
| Follow up with your own users based on what they did in your product | Behavly |
| Rewrite HubSpot nurture emails for each contact | HubSpot Nurture Agent (beta) |
| Build lifecycle flows with AI help, then approve one version per step | Customer.io, Bento or Sequenzy |
| Stop your own sent emails going unanswered | Superhuman, or Gmail Nudges for free |
| Wire a follow-up to one specific app or trigger | Zapier Agents or Lindy |

Two mismatches are worth avoiding. A cold-outreach agent doesn’t know what your users did in your product, so its follow-ups to them read like sales emails. A product follow-up tool has nothing to write from for people who never signed up, and Behavly isn’t built for bought lists.

Whichever you pick, start with approval on and read real emails before anything sends on its own. For the moments worth following up on, see the [behavioral email guide](https://behavly.io/guides/behavioral-email).

## Questions

### What is the best AI agent for follow-up emails?

It depends on who you’re following up with. For cold prospects, look at Instantly, lemlist or HubSpot’s Prospecting Agent. For your own users, look at Behavly; for your own sent threads, Superhuman or Gmail Nudges.

### Is there a free AI follow-up agent?

Gmail Nudges and Help me write are free, though you send each email yourself. Zapier Agents has a free tier of 400 activities a month. Behavly’s free plan includes 50 AI-written emails a month, and Agents start on the $79 Starter plan.

### Can an AI agent follow up automatically without me?

Yes. Instantly’s Autopilot, HubSpot’s **Send automatically** mode and Artisan’s default all send without review. A Behavly Agent also sends on its own unless you turn on its approval hold. Start with review on until you trust what it writes.

### What’s the difference between an AI SDR and a product follow-up agent?

An AI SDR follows up with prospects who haven’t replied, working from contact lists and public data. A product follow-up agent writes to people who already use your product, based on what they did in it.

### Do AI follow-up agents send from my own email address?

Many do. HubSpot and Outreach send from the rep’s connected inbox. Superhuman, Gmail, Lindy and Behavly use your own mailbox. AiSDR and 11x send from mailboxes they set up for you.

## Related

- [What is an AI follow-up agent? How AI agents write and send follow-up emails](https://behavly.io/guides/ai-follow-up-agent)
- [Best AI tools for SaaS onboarding and follow-up emails (2026)](https://behavly.io/compare/best-ai-email-tools-for-saas)
- [The best behavioral email tools for SaaS in 2026](https://behavly.io/compare/best-behavioral-email-tools)
- [What is behavioral email? A practical guide for SaaS](https://behavly.io/guides/behavioral-email)