Can you send contacts from your CRM to squarespace's email platform?

I have a CRM called Follow-Up Boss (Similar to Hubspot). Can I send new contacts from my CRM to Squarespace's email campaign app? I have Mailchimp, but the cost is becoming oppressive based on contacts. I rarely email and I don't want to upload a new list every time a new prospect comes through my system. I have Zapier, but unsure of how to sync new contacts back to SQ. Any insight would be appreciated.