Every survey response updates the MailerLite subscriber it came from, without overwriting anything you did not map
MailerLite gives you clean campaigns, workable automations and a pricing page that does not make a small team flinch. What it cannot do on its own is tell you why a subscriber behaves the way they do. Responsly fills that in, and it puts the answer where MailerLite can use it: on the subscriber record itself.
What actually happens to the subscriber
This is the part most integration pages skip, and it is the part that decides whether you can trust the connection with a real list.
MailerLite’s subscriber endpoint is a create-or-update that is explicitly non-destructive: values are added and updated, and anything omitted from the request is left alone rather than cleared. Three consequences worth knowing before you map a single question:
- A skipped question never blanks an existing value. If the respondent does not answer the question mapped to
job_role, whatever was already injob_rolesurvives. - Existing group membership is never stripped. A survey adds the respondent to the group you chose; it does not remove them from the groups they were already in.
- Group removal is not something a survey can do. If a workflow needs someone moved out of one group and into another, build that as a MailerLite automation triggered by the group the survey added. Expecting the survey to do the removal is the one assumption that will quietly not work.
The conflict rule follows from the same behavior: when a subscriber answers the same survey twice, the second submission overwrites the mapped fields with the newer answers and adds any new groups. Last answer wins on the fields you mapped, and nothing else on the profile moves.
Respondents who are not on your list yet
Because matching is on the email address, a respondent with no existing record is created as a new subscriber in the group you selected. That is genuinely useful — a lead-generation or preference survey builds the list and the segmentation data in one step — but it is not always what you want.
Responsly Flows are the control. A Flow condition can require an email address, or an explicit consent answer, before the response is sent to MailerLite at all; responses that fail it stay in Responsly, still reportable and exportable, just not pushed into your list. For a survey shared publicly or by QR code, that condition is the difference between a clean list and a compliance conversation. Unsubscribes are respected the same way: someone who opted out keeps that status, and a profile update does not resubscribe them as a side effect.
Groups, fields and segments — which to use for what
MailerLite gives you three places to put a survey answer, and picking the wrong one is the most common reason a promising integration goes nowhere.
- Fields hold values. MailerLite fields are typed text, number or date. Put the NPS or CSAT rating in a number field and a segment can compare it properly — scores below 7, scores between 7 and 8 — instead of matching a string exactly. A
last_surveyeddate field is the simplest way to stop re-surveying the same people. - Groups hold categories, and drive automation. A group is both a segmentation unit and an automation trigger, which is why categorical answers belong here rather than in a text field.
- Segments hold the rules. Segments re-evaluate as subscriber data changes, so “detractors not contacted in 30 days” stays correct without anyone maintaining it.
The practical pattern: the rating goes in a number field, the derived category assigns a group, and the segment combines the group with whatever engagement rule the campaign needs.
MailerLite already has a Survey block. When is it enough?
Worth answering honestly, because MailerLite’s built-in block is better than most people expect. It sits in the drag-and-drop campaign editor, offers satisfaction score, NPS, multiple choice, image choice, open question and like/dislike steps, and its rules can move a subscriber between groups and write an answer into a custom field. For a one-question pulse at the bottom of a newsletter, that is the right tool and you should use it.
Its limits are structural rather than a matter of polish. It lives inside a campaign, so it only reaches people already subscribed and already opening that email. Each campaign can carry one survey or one quiz, no more. And results are read per campaign, so a question asked every quarter produces four separate reports rather than one trend.
Responsly answers those three. The same survey runs as a link, a QR code, a website widget or an embedded form as well as from an email, so it reaches people who are not subscribers yet; it can be as long as it needs to be, with logic that adapts it; and every response to a recurring question sits in one place, with Athena clustering the open-ended answers into themes. All of it still writes back to the same MailerLite fields and groups.
Coming from the Typeform route?
MailerLite documents its Typeform connection as a Zap you build in Zapier: a Zapier account, a trigger, an action, field mapping done in a third tool and a task quota to watch. Responsly connects to MailerLite directly with your API key, so mapping happens once inside the survey with no middle layer to debug when a field stops arriving — and the consent and completeness conditions run in Flows before anything is sent.
Campaign patterns that earn their keep
Preference survey that reshapes the send
Ask new subscribers which topics they want and how often. Topic answers assign groups; the frequency answer lands in a field that decides who receives which editions. Honoring a stated preference is the cheapest unsubscribe prevention there is — and asking, then ignoring the answer, is the fastest way to lose the trust you just earned.
Welcome survey that personalizes the first week
Two questions in the welcome sequence — experience level, primary goal — assign the group that selects the onboarding track. Because a group join can trigger an automation, the sequence branches without anyone writing a rule per subscriber.
Recurring satisfaction check that catches decay early
Lists do not fail suddenly; engagement drifts. A short satisfaction survey twice a year writes the rating to a number field and the category to a group. Promoters become the group you ask for reviews, detractors get a real reply from a real person, and the trend across rounds sits in one report rather than scattered across campaign reports.
Post-purchase feedback for creators and small stores
Selling courses, digital products or bookings through MailerLite means the buyer is already a subscriber. A short post-purchase CSAT survey updates their profile, so the next promotion knows whether the last purchase landed well.
Connecting Responsly to MailerLite
- Generate a MailerLite API key in your MailerLite account.
- Open the Connect tab in your Responsly survey and select MailerLite, then paste the key.
- Choose the group subscribers should be added to.
- Map the fields. Email is required for matching; map the rest of the questions to the MailerLite fields that should carry them, creating any missing custom fields in MailerLite first.
- Choose how existing subscribers are handled — create new subscribers only, or update the ones you already have.
- Add a Flow condition if only some responses should be sent — for example, only those with an email address and an explicit consent answer.
The MailerLite integration setup guide has the screen-by-screen detail, including what to check when responses are not arriving.
Pairing it with the rest of the stack
Teams on more than one email platform get the same pattern elsewhere, in each platform’s own vocabulary: the Mailchimp integration uses merge fields and tags where MailerLite uses fields and groups, and Klaviyo and GetResponse cover e-commerce and lifecycle audiences. For destinations with no integration of their own, add Zapier.
Make the next campaign know something new
Keep the surveys short enough that people finish them — skip logic lets three questions feel tailored without becoming ten — and let our email surveys guide handle the timing and framing. Connect Responsly to MailerLite and every rating, preference and comment becomes a field, a group and a segment your next campaign can act on, without touching anything on the profile you did not mean to change.
