Product launches

• We now return per-customer/per-email execution information for email blasts. Try GET /email_blasts/:id/executions to see the data!

Improvements and changes

• We rewrote our email blast execution engine for faster sending and improved reliability
• Performance improvements for estimating message segments as part of campaigns. Additionally, estimated segments are now opt-in: pass ?expand[]=estimated_message_segments to fetch them on campaigns
• Metadata updates on businesses and customers have changed to a “full replace” semantic. This eases syncing concerns. Before, it was difficult to delete keys in metadata because API clients would need to compute the difference between the old and new metadata. Now, you can just pass the full metadata hash to update
• Direct sends via /email_templates/:id/send now bypass daily sending limits to better support the “Test Send Email Template” use case
• Campaigns and triggers now return created_at and updated_at timestamps