Hey @eharrington5 

Klaviyo will sync profiles with Shopify that have not explicitly opted in to receive your marketing emails, since a fundamental piece of the Shopify integration is enabling you to send transactional and post-purchase emails like an Abandoned Cart or Customer Thank You flow.

another reason could be - When a list is created, it defaults to double opt-in, which means the subscriber receives a confirmation email. If they don’t click the link in the email, then they haven’t technically “subscribed”. While Klaviyo recommends double opt-in, you can change the list settings to single opt-in if you want - there are pros and cons to both options.

when importing a list of emails into a list, klaviyo asks you if these emails gave consent to email marketing, if you select yes, they would be marked as Subscribed. If you already did this and it still shows ‘Never Subscribed’, then I am not sure what the issue is, however I would then suggest contacting Klaviyo chat support so that they can look into your account and help you figure out this issue in more detail

I hope this helps

Cheers

Arpit