@lionelbachelart 

The only problem that I can think of here is probably you didn’t set the list to be single opt in and it is still in double opt in settings. So when people subscribe to your form for them to be added to the list they need to cick on a confirmation email. If you want to change this option click on your list, go to settings and there near the buttom you have the double and single opt in options..

Hi @lionelbachelart, 

Thanks for sharing your question with the Community! 

@Bobi N. hit the nail on the head here! If you notice that a user is added into your Klaviyo account, yet not in a specific list that they are supposed to be in, the issue is most likely with your opt-in settings. A list is considered to be Double Opt-In, if there is another method of confirmation needed from the user before they are added to a list. After they submit a form, there is another email sent to their inbox which they need to fill out in order to be added to the form. 

 It is considered best practice, to have your Lists set to double opt-in as this confirms that the profile being added the the lists really does want to receive your marketing and wont negatively affect your deliverability.  You deliverability rate can be lowered if users never open your emails or label you as ‘spam’ in their inbox. However, if you do wish to keep your Newsletter list as Single Opt-in, I would suggest regularly performing Lists Cleaning, which included discovering unengaged profiles in your list and suppressing them in your account. List Cleaning has other positive impacts such as:

• Reducing unsubscribe rates and increase open and click rates
• Increasing your deliverability scores with email providers
• Retaining and engage customers
• Personalizing content based on your best customers

Finally, I’d check out these other posts to gain more insight into the topic! 

Thanks for your participation in the Community!

-Taylor