Hi OnlineMoneyGR,
Thanks for hopping in the forum! The wordpress plugin uses MailChimp’s default login process which is double opt-in. We recommend double opt-in because it provides verifiable proof that a subscriber opted into your list.
MailChimp does have an integration with Wufoo which offers a single opt-in option. Learn more about that integration here: https://wufoo.com/2010/04/13/create-single-and-double-opt-in-forms-for-mailchimp-and-campaign-monitor-integrations/
MailChimp also has other integrations with services that have single opt-in. Those can be found in the MailChimp Integrations directory: https://connect.mailchimp.com/
I will also take note of your feature suggestion.
-mcd
