Unfortunately, apps cannot be automated.
And Airtable Automations have very limited email capability (for example, they can’t send HTML emails).
So you would likely need to use Airtable Automations to write your own custom JavaScript code which triggers SendGrid’s API, and then schedule it to run nightly (or weekly or hourly).
However, my preferred way of doing this is to not write any JavaScript code at all, which you can do by using a no-code automation platform like Integromat. Integromat can be scheduled to send your emails nightly via SendGrid, and you don’t need to write any code.
(Note that I am a professional Airtable consultant and a Registered Integromat Partner, and the Integromat link contains my personal referral code.)
