MailChimp is a tool for managing email campaigns. A campaign is created by creating a mailing list which users can subscribe to. By default, subscribing to a campaign is double opt-in, meaning that not only does a user have to sign up [by entering their email address to a form], but must also click a link within an email sent to that address to be added to the list. This is probably a good default because it leads to better list quality; it is a great way to prevent unauthorized sign-up. However, it complicates the process because now sign-up is a two-step processing. If a user forgets to click the link, they never get subscribed to the list.
We can help you write function auto add customer’s email into list bypass MailChimp double-opt in confirmation email. Meaning that only does a user have to sign up. If you want I can help you write more extra functions after submit.