Double opt in means a new subscriber is sent an email asking them to confirm, and they only become active once they click the link in it. Single opt in means they are active the moment they sign up.
A new list starts on single opt in. Double opt in is there when you want it, and you switch it on list by list. If you would rather every new list started with it on, tick Default new lists to double opt-in in Settings.
Which should you use?
Double opt in gives you a smaller but more engaged list, fewer mistyped and fake addresses, and proof of consent, which matters under GDPR and similar rules. Single opt in gives you a bigger list and lets you deliver a lead magnet instantly, at the cost of more bad addresses. Neither is wrong. It depends on what the list is for.
Setting it on a list:
- Open Lists and edit the list.
- Tick Require double opt-in confirmation.
- Under Confirmation email, write your own subject and body if you want to. Merge tags such as {{first_name}} work in both.
- Put {{confirm_url}} where the link should go, for example inside a button or a link. If you leave it out, a Confirm subscription button is added for you, so the email can never go out without its link.
- Save.
What happens when someone signs up:
The confirmation email is sent straight away, through your own sending connection, the same one your broadcasts use. That means it appears in your provider's logs like any other email, and your daily limits, rotation and failover all apply. It comes from the list's own sender details.
Until they click the link their status is pending. Pending subscribers are never included in broadcasts.
When they click, they become active, the date they confirmed is recorded, and everything that was waiting for them starts.
If someone who is still pending fills the form in again, they stay pending and are sent the confirmation again. That is usually somebody who never saw the first one.
How automations treat it:
- Joins a list. On a double opt in list the person is taken into the automation but held at the very start. Nothing is sent to them. The moment they confirm, the automation begins, so your welcome email arrives right after the confirmation click and not before it. If they never confirm, they leave the automation after 30 days with the reason never confirmed their subscription. On a single opt in list this trigger works as it always has, immediately.
- Confirms their subscription. This starts an automation when someone clicks the confirmation link. You can pick a list, so it only starts for confirmations on that list, or leave it on any list.
Use one or the other for a welcome series, not both, or the person will be in two automations.
Overriding it on a form:
Each form carries an opt in policy 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.
Imported subscribers:
People brought in by an import, a sync or a bulk add are never sent a confirmation request, because they did not just sign up. This is part of the silent import lock.
Safe Mode:
While Safe Mode is on, confirmation emails are held back like every other email. Switch Safe Mode off before you start taking double opt in sign-ups.
If a confirmation does not arrive:
- Check the sending connection works by sending yourself a test broadcast.
- Check Safe Mode is off.
- Look in your provider's logs for the address. The email is sent the moment the form is submitted.
- Ask the person to fill the form in again. They will be sent a fresh copy.