Hi @angelalow, welcome to the community!

If you have two separate Klaviyo accounts, the emails between them should not overlap as they are completely separate instances.

A few things to check:

• If you recently uploaded email addresses, did you make sure you were logged into the correct Klaviyo account?  You can look at your import history by clicking on your main List and go to “Imports” - it should show you recent imports. 
  
  See here:

  

  I haven’t imported any contacts in this test account, but if you have made a recent import it will be shown here.

• I assume you have two different ecommerce sites for each, make sure the integration of Klaviyo is connected to the correct account and they match. 
  • Go to your Settings → Integrations → Ecommerce Platform (Shopify?) and make sure the Store URL is the right one for the Klaviyo account.  See here:

    

• Lastly, if you’re using any third party tool or plugins (quizzes, surveys, popup tools, etc) that captures emails, make sure they are connected to the right Klaviyo Account. 

Hopefully that will help you get started on troubleshooting what’s happening!