Where is the issue coming from?
Klaviyo offers a "subscribe to the newsletter" module that you can integrate into your shop. However, when people subscribe to it, their email addresses are not transferred to Shopify, they are sent to the Klaviyo database only. So those email addresses are not visible from the Shopify back office.
How to fix it?
To prevent this issue, Quanticfy uses a workflow automation tool called Make that allows us to synchronize your shop with Klaviyo for all upcoming prospects. This will automatically add all new addresses gathered through the Klaviyo newsletter module to your Shopify database.
⚠️ We don't synchronize past data by default (we don't gather the addresses that were input into Klaviyo before you connected to Quanticfy). If you need us to do so, please open a ticket by clicking on the chatbot (right bottom corner of this page). Please note that this might significantly increase your database size, and therefore your Quanticfy rates.
If you need help with connecting Klaviyo to Quanticfy, please visit this page.