How to Disable the Mailchimp Double Opt-In Using WordPress
MailChimp, by default, requires a double opt-in process for subscribers to join a list. MailChimp uses this feature to avoid lists being cluttered by spammers and invalid e-mail addresses. In some instances, though, the double opt-in feature can lose new subscribers if the opt-in e-mail isn’t confirmed or if the e-mail gets sent to the spam or bulk folder.
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