The confirmation email does not arrive or goes to spam

A person signs up and never gets the email asking them to confirm, or it lands in spam. First open the person in Audience > Contacts (the timeline shows optin_requested when the email was queued), then search the address in Deliverability > Sending Log and read the status. Causes, most likely first:

1. It is still queued. The scheduler is not running. Open Settings > Scheduler and click Run the scheduler now. See A scheduled campaign did not go out.

2. Delivery is not working. In Settings > Compliance, card Confirmation email, type your address in Send a test to and click Send a test. A red box shows the reason. See Emails are not sending.

3. The form does not ask for confirmation. The default is Ask new subscribers to confirm by email in Settings > Compliance, but a form or flow can subscribe people at once. Check the form in Audience > Forms or the flow's trigger. See Double opt-in and the confirmation email.

4. The contact cannot be asked. Only Pending or Transactional contacts can be asked ("Only a contact who has not confirmed yet can be asked to confirm."). An address on the suppression list gets nothing. See Bounces, complaints and the suppression list.

5. A throttle held it back. One confirmation per contact every 5 minutes. Signup forms send at most 3 per address a day and 20 per network an hour.

6. The people were imported as pending. An import never emails anyone by itself. In Settings > Compliance, use Send confirmation to pending contacts: choose Who, click it, then Send the emails.

7. It went to spam.

   • Use a Default From email on your own domain (Settings > General), not @gmail.com or similar.
   • Add SPF, DKIM and DMARC: Settings > Sending > Is your site ready to send? > Check my domain. See Is my site ready to send email?.
   • Do not send through plain WordPress mail: install an SMTP plugin, or choose Mailgun or SendGrid.

8. The link fails. "This link has expired" after 30 days (The confirmation link works for): the page offers Send me a new email. "This link does not work": the site's secret keys (salts in wp-config.php) changed; new emails work. A mail scanner opening the link does nothing on purpose: the person must press Confirm my subscription.

Next: Settings: Compliance.