When creating a custom report to identify the best times to send your emails, what should you select for your primary data source?

HubSpot’s Marketing email analytics data source contains engagement and delivery metrics needed for custom marketing email reporting. For identifying send-time patterns, HubSpot uses Marketing email analytics as the primary data source and Marketing email as the additional data source. Time-based fields such as delivered date and hour of day are report configuration fields, not the primary source. Selecting the analytics source first ensures the report can measure performance by send timing.