Hey @lisapineau ,
You can add a 301 redirect from your deleted collections or archived products to ensure that users won’t come across a 404 Error from a backlink.
Shopify has an article in their help center on how to do that: https://help.shopify.com/en/manual/online-store/os/menus-and-links/url-redirect
Just go through this process for all collections/products that you are deleting or archiving and you should be good to go!
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