Is there a segment list size limit? 

No, there isn't. However, you will see longer processing times for segments larger than 1.3 million subscribers. If your list is larger than 1.3 million subscribers, please reach out to our White Glove team ( for an SLA. 

Are segments available for both campaign messages and automated journeys? 

Yes! View Branching on segments to learn more.

Does Attentive support both Klaviyo segments and lists?

Yes, we support both!

How do I exclude a Klaviyo segment from my next send? 

You can exclude a Klaviyo segment using the exclude segment option when creating a campaign message.