Hi ​@Sam91 

Thank you for posting in the Community!

I would recommend you to have a custom property mapped to active subscribers - then you can easily filter then out of your replenishment flows and other irrelevant flows that could create noice in their inbox.

If you are new to custom properties there is an easy guide here - other wise, look up one of your active subscribers in Klaviyo and see if the data is already available from your subscription platform. 

I hope this helps!