Double opt in means a new subscriber receives an email asking them to confirm before they are treated as active. Single opt in means they are active immediately.
Which should you use?
Double opt in produces a smaller but far more engaged list and gives you proof of consent, which matters under GDPR. Single opt in produces a bigger list with more bad addresses. For most list building, double opt in is the better long term choice.
Setting it on a list:
Edit any list and switch on Require double opt-in confirmation. You can customise the subject and body of the confirmation email. The body must contain the {{confirm_url}} merge tag, which becomes the confirmation link.
Until someone clicks that link their status stays pending, and pending subscribers are not included in broadcasts.
Overriding it on a form:
Each form carries an opt in policy setting with three choices:
- Follow the list setting, which is the default
- Force confirmation on, regardless of the list
- Force confirmation off, regardless of the list
This exists because the right answer changes by context. A lead magnet where someone expects an instant download is a reasonable place to skip confirmation, while a general newsletter signup is a good place to require it.
What confirmation triggers:
Confirming fires the confirmed trigger, so you can start a sequence at the moment someone proves their address is real. That is usually the best place to deliver a welcome series.
Imported subscribers:
People brought in by an import are never sent a confirmation request, because they did not just sign up. This is part of the silent import lock.