Hi @christienlouviere, welcome to the community.

My experience is that during the test sending emails of Klaviyo, emails can end up in the Spam folder especially if you are new to Klaviyo, but typically limited to just test sends.

Since the Spam filters in most inbox providers (Gmail, Yahoo, Outlook, etc) are highly personalized (think of it like the recommendation algorithm), these can vary from user to user based on their interaction with emails from Klaviyo.

If you are new to Klaviyo and migrating to Klaviyo with a dedicated IP, a good first practice is to make sure your account is properly “warmed.”  You can read more about this process here:

• How to migrate your dedicated sending domain from a previous email service provider (ESP) to Klaviyo

Otherwise, implementing good “deliverability practices” is the best way to stay out of the Spam folders moving forward.

Hope this helps!