Mailerflow Automation Builder: From One Sentence to a Live Workflow

The Mailerflow automation builder turns a plain-language sentence into a working automation — trigger, waits, conditions and emails — which you review and edit in a visual builder before anything goes live. You describe the sequence you want, Mailerflow drafts it, you tighten the details, then you activate. This guide walks through that flow end to end, with the exact steps, a worked example and a way to confirm the automation is actually running.

What You'll Set Up (and What You Need Before You Start)

By the end you'll have a live automation built from a sentence you typed, with at least one email and one wait, tested against a real contact record.

Before you start, you need:

• A Mailerflow account.
• A verified sending domain. Mailerflow walks you through DKIM, SPF and DMARC setup and verifies it automatically.
• At least one way for contacts to enter the automation: an embeddable signup form with double opt-in, a CSV import, or an event or webhook from your app.

Two limits are worth knowing up front, because they affect how many automations you can keep running at once. Active automations are capped per plan — 3 on Free, 10 on Starter, 50 on Growth, unlimited on Pro and above — and AI actions are metered monthly, from 100 on Free up to 30,000 on Scale. Current numbers live on the pricing page.

The AI automation builder only drafts. Nothing is sent and nothing goes live until you approve the workflow and activate it.

Step-by-Step: Building an Automation in Mailerflow

1. Open the automation builder

Go to Automations and start a new automation, then choose the AI builder entry point rather than a blank canvas. You should see a single text field where you describe the workflow.

Verify: the screen shows an empty description field and a draft button, not a pre-built template.

2. Describe the workflow in one or two sentences

The draft is only as good as the sentence. Name the trigger, the timing and the goal.

• Vague: "Send some emails to new people."
• Workable: "When someone signs up for the newsletter, wait 2 days, send a welcome email, then if they haven't clicked anything in 5 days send a nudge with a product highlight."

One goal per automation. If you describe two goals in one sentence, the draft will merge them into a single tangled flow.

Verify: before you submit, reread the sentence and confirm it contains a trigger, at least one wait and one condition.

3. Review the drafted workflow

Mailerflow returns a draft with the trigger it chose, the waits, the conditions and the emails. Read it in order and check four things:

• Trigger: does it match the signal you meant — a signup, an event, a date, inactivity or website behavior?
• Waits: are the durations realistic for your sales cycle, or just defaults?
• Conditions: can each one actually be true with the data you're collecting?
• Emails: is the sequence order sensible, and is anything missing?

Verify: you can point at each block and say what it does. If you can't, it needs editing before you continue.

4. Edit the draft in the visual builder

Now move blocks around, change wait durations, tighten conditions, and insert webhook or AI steps where they earn their place. A webhook step is useful when the automation should notify another system — for example, alerting a sales channel when someone reaches a specific email.

Verify: the flow reads left to right without a branch that can never fire.

5. Refine the emails

You can edit blocks directly in the visual block editor — headings, heroes, products, columns, social links — or start from a reusable template. If you'd rather describe the change, the AI email builder takes a description and returns a complete responsive design with subject lines and preview text. The AI email builder walkthrough covers that side in more detail.

Verify: preview each email on desktop and mobile, and check the subject line and preview text render as intended.

6. Add personalization or website-behavior data

If the automation should react to what a contact read or did, connect website-behavior data through the JS SDK and use it in conditions or AI personalization steps. Skip this if you don't have the data yet — a condition on an untracked event will simply never fire.

Verify: the events you plan to branch on are arriving before you rely on them.

7. Set entry conditions and re-entry rules

Decide who is eligible to enter and whether a contact can re-enter after finishing. Without a re-entry rule, a contact can loop back through the same sequence.

Verify: the entry conditions exclude the people you don't want, such as existing customers.

8. Activate

Turn the automation on. The status should change from draft to active, and the entry counter should start at zero.

Verify: the automation shows as active and accepts a test contact.

A Worked Example: Trial Nudge Sequence for a SaaS Team

The following is an illustrative scenario, not a customer story. A small SaaS team wants to reduce trial drop-off. They type this sentence into the builder:

"When someone starts a trial, wait 1 day, send an onboarding email about what to do first. If they haven't clicked anything in 3 days, send a nudge with a product highlight. If they still haven't clicked after 4 more days, offer a walkthrough. Otherwise send advanced tips. Then wait until trial day 12 and send what happens at trial end."

The draft comes back as:

Trigger: signup with tag 'trial-started'
  └─ Wait 1 day
      └─ Email 1: Onboarding — what to do first
          └─ Wait 3 days
              └─ Condition: no link click in last 3 days
                  ├─ Yes → Email 2: Nudge + product highlight
                  │         └─ Wait 4 days
                  │             └─ Condition: still no click
                  │                 ├─ Yes → Email 3: Offer a walkthrough
                  │                 └─ No  → Email 4: Advanced tips
                  └─ No  → Email 4: Advanced tips
                      └─ Wait until trial day 12
                          └─ Email 5: What happens at trial end

After review, the team makes three changes: they shorten the first wait from 2 days to 1, replace a generic subject line with one generated by the AI email builder, and add a webhook step that notifies their team channel when someone reaches Email 3 — the moment the trial looks at risk.

Which trigger maps to which signal matters here. A signup trigger fires on form submission or list entry. An event trigger fires when your app reports something, like a trial starting. A date trigger fires relative to a stored date, such as trial end. An inactivity trigger fires when a contact stops engaging. A website behavior trigger fires on page visits or actions tracked through the JS SDK. The trial sequence above uses a signup or event trigger at the top and a date trigger for the final email.

How to Check the Automation Actually Works

Don't trust the diagram — walk a contact through it.

• Create a test contact. Import one via CSV, or add it through the signup form and complete double opt-in.
• Trigger the entry. Apply the tag or fire the event the trigger listens for.
• Watch the timeline. Open the contact's activity and confirm each step appears in order, with waits respected.
• Confirm the automation is live. The status should read active and the entry count should have incremented by one.
• Check the numbers. Analytics show delivery, bounces, complaints, clicks and approximate opens per email, so you can see whether Email 1 actually went out.
• Confirm webhooks fired. Signed real-time webhooks include retries and delivery logs — check the log entry for your test run.
• Confirm suppression works. Bounces and complaints are suppressed automatically, so a test address that hard-bounces stops receiving mail rather than looping.
• Check timing behavior. If you enabled "send when the contact is most active," confirm the send landed when you expected. A/B testing applies only where you set it up, so don't assume it's running by default.

Common Mistakes and How to Fix Them

Two goals in one sentence. The draft merges them into one flow with confusing branches. Fix: split into two automations, one goal each.

Default waits left untouched. A two-day wait copied from the draft may not match your sales cycle. Fix: set each wait against how long your buyers actually take.

Conditions on events you don't track. The branch never fires and the automation looks broken. Fix: confirm the event or website-behavior data is arriving before you activate.

First email sent before double opt-in completes. Fix: gate the first send behind the confirmation, or start the automation on the confirmed event rather than the raw signup.

No re-entry rule. Contacts loop through the sequence repeatedly. Fix: decide explicitly whether re-entry is allowed and after how long.

Activation fails silently. You may have hit your plan's active-automation limit. Fix: check the plan limits and either archive an old automation or upgrade.

AI actions run out mid-build. Lower plans meter AI actions monthly. Fix: use AI where it saves the most time and edit the rest by hand.

Next Steps After Your First Automation

Once one automation is running, the same builder handles the next layer. Add a branch based on website behavior, or an AI personalization step that tailors copy to what each contact read. Dynamic segments can be built the same way — from a plain-language description — so you can target the people your automation identifies. A/B testing on the campaign side is a good place to test subject lines before you commit them to an automation.

Two things worth knowing as you scale: paid plans include unlimited emails, so adding steps doesn't change your send cost, and free migration help covers contacts, suppression lists, templates and core automations on eligible paid plans if you're moving from another tool. The automation docs list every trigger type, and the pricing page has current plan limits.

FAQ

Does the AI automation builder activate the workflow automatically? No. It drafts the trigger, waits, conditions and emails for review. Nothing goes live until you activate it.

What triggers can I use? Signups, events, dates, inactivity and website behavior.

Can I edit the drafted emails? Yes — in the visual block editor, from a reusable template, or by describing the change to the AI email builder, which returns a responsive design with subject lines and preview text.

Do automations count against my email quota? Paid plans include unlimited emails. Active automations and AI actions are metered per plan, so check the pricing page for current numbers.

Can I use webhooks inside an automation? Yes. Webhooks are signed, delivered in real time, retried on failure and logged.

Describe your next email or automation in one sentence and let Mailerflow's AI build it — free plan, no credit card.