Why are my Opt-in Emails Not Being Sent?
If you have enabled the Double Opt-in feature on the Settings > Project Settings page and the opt-in confirmation emails are not being sent to your users, then you will want to ensure that you have an email message with the trigger "applies (opt-in confirmation requested)" added to your project on the Email > Messages page.
When the Double Opt-in feature is enabled, Prefinery automatically adds an email message named "Opt-in Confirmation" with the trigger "applies (opt-in confirmation requested)" to your project. If this email message is no longer found in your project, then you most likely accidentally deleted it while setting up your project. There are two ways to re-add this message:
Option 1: Disable and Re-Enable the Double Opt-in Feature
Go to the Settings > Project Settings page and slide the Double Opt-in toggle to the Off position. Then, click the Save button at the bottom of the page to save this change. Now, return to the Settings > Project Settings page and slide the Double Opt-in toggle to the On position and save the change. You should now see that the email message named "Opt-in Confirmation" appears in your list of email messages on the Email > Messages page.
Option 2: Add the Opt-in Confirmation Email Manually
Go to the Email > Messages page and click the Add a Message button. Author a new email message by filling out all of the fields, making sure to set the trigger to "applies (opt-in confirmation requested)".