Single Opt-In

When a single step, like entering an email address into a collection field or selecting a checkbox, is taken to subscribe to an email marketing list. This practice is considered dangerous for a sender because nothing is preventing typos or forged email addresses from being added to your subscriber lists. With a single opt-in, there could be risks to your email delivery and reputation due to both a high number of bounced addresses and from blacklistings due to high spam traps.

Confirmed Opt-in

In this situation, your subscriber receives a confirmation “welcome” email or the start of a welcome series once they opt in. This confirms that your recipient wants your email (and did not unknowingly sign up or change their mind). This form of consent decreases the likelihood of anyone being on an email marketing list long-term who does not want to be, but just as importantly verifies to you, the sender, that their email address actually exists. This also helps prevent frequent “typo” and “recycled” spam trap hits.

Pre-Selected Opt-in

In this scenario, a subscription check box is pre-selected for users to receive promotional emails where they would be including their email address (during a purchase process, for example). By leaving the checked box intact, users consent to receive email from you. This option is not flawless, as some users may not realize they’ve given their permission to receive marketing email and could be much more likely to report your email as spam, resulting in damage to your sending reputation and your company.

Pre-Selected Opt-in With Confirmation

This version of “pre-selected” consent will send a confirmation email to any recipient who has left the pre-selected opt-in checkbox intact. But unlike “pre-selected opt-in,” the confirmation content helps decrease the possibility of unintentional subscribers, therefore reducing the potential for spam complaints.

Co-Registration

This practice gives users the option (or forces them) to agree to receive email from third parties. Co-registration is very risky and should be used with caution because it can be confusing to recipients if they did not remember leaving boxes checked and accidentally signed up for emails they did not expect. This can easily lead to spam reports and corresponding email deliverability issues.

Double Opt-In

This is considered the best form of consent a user can provide a sender, since it requires a secondary action from the email address owner to confirm subscription to an email list. This typically comes in the form of a confirmation link call to action, a URL to post in a browser, etc. For senders, this is the ideal method of collecting addresses because you demonstrate a genuine desire to make sure your subscriber absolutely wants your content, and it sets an effective foundation for your sender/recipient relationship moving forward.