Editing Double opt in vs. single opt in (section)

=== Troubleshooting ===
- If subscribers are not receiving the confirmation email in the '''double opt-in''' process, check the following:
  - Ensure that the email address entered is correct.
  - Verify that submission is tagged as "unconfirmed" in the list settings.
  - Check your email deliverability settings.
- For '''single opt-in''', if users complain about receiving unwanted emails, promptly address the complaints by ensuring they are aware of the opt-in model used.