Double opt-in means a new subscriber confirms by email before joining your list. It keeps typo’d and fake addresses out, produces cleaner engagement data, and gives you a confirmation record for consent. ChimpMatic supports it with every provider, but each platform handles confirmation differently. Here is exactly how it works for each one.
How each provider handles confirmation
Mailchimp: per form, your choice
Choose single or double opt-in directly in the form’s Chimpmatic tab. Double sends Mailchimp’s confirmation email and the subscriber joins the audience only after clicking it; single subscribes immediately. Different forms can use different settings. Mailchimp setup guide
Brevo: direct subscribe or confirmation email
Per form, subscribe contacts directly or have Brevo send its confirmation email first. The confirmation template and its content are managed inside your Brevo account. Brevo setup guide
MailerLite: follows your account setting
MailerLite controls double opt-in globally for API subscribers: enable it in your MailerLite settings and confirmations apply to subscribers added by your forms; disable it and they join immediately. ChimpMatic respects whichever you chose. MailerLite setup guide
Klaviyo: follows the selected list
Klaviyo configures opt-in per list. If the list you picked uses double opt-in, new profiles receive Klaviyo’s confirmation email before being subscribed; single opt-in lists subscribe on submission. Change it on the list in Klaviyo. Klaviyo setup guide
Single or double: which should you use?
Use double opt-in when list quality and provable consent matter more than raw signup count: newsletters, lead nurture, anything operating under GDPR-style consent expectations. Use single opt-in when the subscription is secondary to a transaction the visitor clearly initiated, like a quote request form, and confirmation friction costs you real contacts. Whichever you choose, pair it with a clear consent checkbox: ChimpMatic can require an opt-in checkbox before any subscriber data is sent at all.
Test your confirmation flow
- Configure the form, then submit a test entry with a real inbox you control.
- Confirm the provider’s confirmation email arrives and its link works.
- Check the subscriber’s status in the provider before and after confirming: pending first, subscribed after.
FAQ
The confirmation email never arrived. Why?
Check spam, then verify the sending domain and confirmation template in the provider’s own settings. The confirmation email is sent by the provider, not by your WordPress site, so deliverability is configured there.
Can I customize the confirmation email?
Yes, in the provider’s dashboard: Mailchimp and Brevo let you edit the confirmation template; Klaviyo configures it on the list. MailerLite manages it with the account-level double opt-in setting.
Does double opt-in change what data is sent?
No. The same mapped fields are sent either way; see external services for the full disclosure. The provider simply holds the subscriber as pending until they confirm.
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