INTEGRATIONS
Keep your existing mailer when you change funnel builders
Switching funnel builders doesn't have to mean switching mailers. Most builders offer a native integration, a webhook or API connection, or a Zapier-style connector to tools like Kit, Mailchimp, ActiveCampaign, MailerLite, AWeber or Brevo; check which option your target platform actually supports before assuming a migration. The real risks are duplicate contacts from repeated opt-ins and unclear ownership of transactional versus marketing sends.
Two paths: built-in email or your existing mailer
Every all-in-one funnel builder ships its own email tool, and switching platforms is the natural moment to ask whether to keep using it. Consolidating into the builder's own email means one login and one bill; keeping Kit, Mailchimp, ActiveCampaign, MailerLite, AWeber or Brevo means preserving deliverability history, existing automations and a tool your team already knows. Neither is automatically right; it depends on how much you've already invested in the mailer's own automation logic.
How funnel events actually reach your mailer
Three mechanisms connect a funnel builder to an external mailer, and platforms differ in which they offer: a native integration (a built-in connection the platform maintains for a specific mailer), a webhook or API connection (the funnel builder sends data out, or your mailer pulls it, on events like form submission or purchase), or a Zapier-style connector (a third-party automation layer that relays events between the two). Check which of these your specific platform supports for your specific mailer before committing; a native integration for one mailer doesn't guarantee one exists for another.
Where duplicate contacts come from
Duplicates usually trace back to the same contact entering the mailer through two different paths, a funnel opt-in and a separate lead magnet, for example, without the mailer recognizing them as the same person. Check whether the connection you're using matches contacts by email address before creating a new record, and confirm what happens if someone opts in twice through different funnel steps. This matters more right after a migration, when both the old and new funnels can briefly be live at once.
Who sends what: transactional versus marketing mail
Order confirmations, receipts and password resets (transactional mail) usually need to reach the inbox regardless of marketing consent, while newsletters and promotional sequences (marketing mail) depend on opt-in status and unsubscribe handling. Decide up front whether the funnel builder or the external mailer sends each type, so a customer isn't double-emailed by both systems for the same purchase, and confirm your mailer's terms allow transactional sends if you plan to route them there.
What to check in your own account before you commit
Before switching funnel builders with a mailer you want to keep: confirm the specific integration exists for your mailer on the new platform, test a single contact through the connection end to end, and verify what data actually transfers (email only, or full contact fields and tags). Assumptions based on another platform's integration list don't carry over; the only reliable check is the one you run in your own accounts.
When keeping your mailer is worth the extra moving part
Keeping an external mailer adds a connection to monitor and, usually, a second monthly bill on top of the funnel builder itself. It's worth that overhead when you have deliverability history built up, automations too complex to rebuild quickly, or a team already trained on the tool. For a straightforward opt-in and follow-up sequence, consolidating into the funnel builder's own email, where one is included, removes a moving part. Compare the full stack cost with the cost calculator.
Questions people also ask
Can I use Mailchimp with any funnel builder?
It depends on the platform. Some offer a native Mailchimp integration, others require a webhook or API connection, and some need a third-party connector like Zapier. Check your specific platform's integration list, and test the connection with one contact, before assuming it works.
Why did a contact get added to my mailer twice?
Usually because they entered through two different paths, two funnel opt-ins or a funnel plus a separate form, that weren't matched by email address on the mailer's side. Check how your specific connection handles duplicate matching before running larger campaigns.
Should transactional emails come from the funnel builder or the mailer?
Either can work, but pick one and route all transactional mail through it consistently. Sending the same receipt from both systems is a common source of customer confusion after a migration.
Is it cheaper to consolidate into the funnel builder's own email?
Often, since it removes a second subscription and a connection to maintain. Whether it's worth the switch depends on how much automation and deliverability history you'd need to rebuild; price both paths with the cost calculator.