Single Opt-In

In a Single Opt-In system, subscribers enter their email address on a sign-up form and are immediately added to the mailing list without needing to confirm their subscription via a follow-up email. This method simplifies the subscription process but may result in a higher risk of invalid or mistyped email addresses.

While Single Opt-In can boost subscription rates, it may lead to lower list quality and higher rates of spam complaints. Marketers using this approach should regularly clean their email lists and monitor engagement to maintain list health and deliverability.