We are currently using Mailchimp to send a daily newsletter to our subscribers. The newsletter features the Catholic saint whose feast day is on that particular date. Our current process is that the information for the relevant saint is pulled from a SQL database and the Mailchimp API is engaged to pull up an existing template in Mailchimp and insert the data for the saint into existing placeholders in the Mailchimp template. From there a new campaign is created via the API using the newly created email and is sent right away. We would like to replicate this process in Hubspot but I need guidance in which APIs from Hubspot would be involved and using those APIs can I send to an entire list at once or do I have to iterate through each contact on the list? We send to ~60k individual contacts everyday through Mailchimp for just this newsletter.