Automated follow-up emails based on what users do (with 6 example paths)

An automated follow-up email based on user behavior is an email your product sends to one of its own users because of something they did or didn’t do, like signing up and stopping, opening the pricing page twice or going quiet for two weeks. Each next email then waits on that person too, until they act or a set time passes, and the whole follow-up path ends when they reply or reach the goal it was built for.

This guide is about following up with people who signed up for your product, not with sales prospects. For tools that chase cold emails nobody answered, see the comparison of AI follow-up email tools.

Behavior-based follow-ups vs. drips vs. cold follow-up sequences

A drip suits things everyone should hear in the same order. Most email after signup depends on what someone has already done, and that is what a path is for. For the wider practice, see behavioral email for SaaS.

6 example follow-up paths for a SaaS product

These are for Paperlark, a made-up proposal tool for freelancers and small studios: a 14-day Pro trial, then a Free plan with three proposals a month. Activation is the first proposal sent (proposal_sent). For 20 more triggers, see these behavioral email examples.

1. Signed up, but never set anything up

Who enters

Did signed_up, never proposal_sent, not seen for a day (not an hour: many come back on their own).

The path

An email naming the one step left. Branch: clicked a link in it within 3 days? Yes: wait 2 days, then offer to look over their draft. No: two lines in the same thread asking what work they usually quote for.

Goal

proposal_sent, which ends the path at once.

2. Visited the pricing page twice

Who enters

Visited /pricing, never did upgraded, seen in the last 7 days.

The path

A branch first: visited /pricing again within 7 days? No: stop, since one visit is curiosity. Yes: an email on the plan that fits what they use, then a branch: clicked it within 3 days? Yes: stop. No: one short follow-up in the same thread, such as on paying yearly.

Goal

upgraded.

3. Used a feature once, then not again

Who enters

Added a deposit to a proposal (deposit_added) for the first time.

The path

A branch first: added one again within 10 days? Yes: stop, it’s becoming a habit. No: one email written from the proposal where they used it, then stop.

Goal

The next deposit_added.

4. Went quiet for 14 days

Who enters

At least five visits and three proposals sent, not seen for 14 days. For someone who came twice, two quiet weeks say little.

The path

An email about their last piece of work. Branch: logged in within 5 days? Yes: stop. No: two lines in the same thread with one question, such as whether a new project is coming up.

Goal

proposal_sent: real use, not just a login.

5. Payment failed (an event from your server)

Who enters

Everyone your server sends payment_failed for, each failure a new case.

The path

A template with the amount from the event, sent right away within working hours. Wait 3 days, then an email written from what their account has at stake, like proposals awaiting a signature. Wait 4 days, then a last notice.

Goal

payment_succeeded, which ends the path whatever step they’re on.

6. Trial ending (an event from your server)

Who enters

Everyone your server sends trial_ending for, three days before the end, once per person.

The path

An email written from their trial. Branch: visited /pricing within 2 days? Yes: an email on which plan fits. No: when the 2 days run out, a template reminder with the end date from the event.

Goal

upgraded.

How to build these paths in Behavly

Behavly tracks what each signed-in user does in your product and runs paths like these: an AI follow-up agent for your own users.

1. 1Track. Add the snippet from Tracking → Setup to your signed-in pages; it ties activity to the signed-in person with no identify call. Send actions like proposal_sent with behavly.track.
2. 2Describe the path. In Automations, choose Pattern Campaign or Trigger Campaign. Under Describe the path, write it as the examples above are written and choose Build the path: Behavly lays out the emails, waits and branches for you to check. Nothing sends until you activate.
3. 3Paths 1 to 4 start from a group. Describe it under Looking for another pattern? and see who matches, and how many, before Add this pattern. Always on re-checks the group every 10 minutes and takes each person in once, as they join; Once sends to the people in it when it starts.
4. 4Paths 5 and 6 start from an event. Make the trigger in Triggers and send it from your server with a Send events only key; a Trigger Campaign takes the person in as it arrives. Set If it happens again to A new case each time for payments, Once per person for trials.
5. 5Let Behavly Agent write. A Plain text by Behavly Agent step is written for each person from their activity, in your sender’s voice, and reads the earlier emails on the path so the second picks up from the first. Instructions for Behavly Agent says what it is for. For exact facts, an Email step sends your template Send as designed, with {{event.amount}} filled in from the event.
6. 6Set the goal and exits. Pick the Goal, and turn on They reach the goal under Leave when; They reply is on by default. Someone who stops matching the group isn’t taken off the path, so these are what stop it.
7. 7Read before it sends. Preview writes any email step for a real person, and Test sends you the whole path. Review is off by default: turn on Hold Behavly-written emails for approval to release each written email yourself.

Emails go out from your own mailbox over IMAP/SMTP, or your account at an email service such as Resend or Amazon SES, connected in Settings → Email, on weekdays from 9:00 AM to 6:00 PM in each person’s timezone by default. Every campaign type runs on every plan, Free included; written emails count toward your plan’s monthly personalized emails.

Replies to emails sent through an email service aren’t read back into Behavly, so a replied branch or They reply exit can’t see them. Where replies should decide, send from an IMAP/SMTP mailbox.

Mistakes to avoid

• Following up on one signal. Wait for the second pricing visit, or the visit plus a plan limit.
• Waiting on the calendar. A fixed three-day wait reminds people who did the step yesterday. Wait until they act, with a limit.
• No goal or exit. The person who upgraded on Tuesday gets “ready to upgrade?” on Thursday.
• Treating opens as interest. Some mail apps load images on their own. Branch on clicks, logins, visits or actions.
• Stacking paths. One person can qualify for three in a week. Behavly’s Agent guardrails cap it at 3 emails in any 7 days, with campaigns 24 hours apart, by default.

How to measure automated follow-up emails

• One goal per path. Count who reaches it, such as upgraded, not who opened.
• Credit the last email before it, and keep counting a few days after the path ends. Behavly does both, counting for 7 days after a person’s last email.
• Read each step’s numbers. Clicks with no goal mean the email promises something the next screen doesn’t give.
• Compare with doing nothing: similar users from before the path started, or a few held out.
• Change one thing at a time. Behavly’s A/B test names a winner only once each version has 30 sends and the gap is unlikely to be chance, and Path review suggests changes each Monday once a campaign has sent 20 emails.