A Single Send is a one-time, non-automated email message delivered to a list or segment of your audience. A Single Send may be sent immediately or scheduled for future delivery.
Single Sends can serve many use cases, including promotional offers, engagement campaigns, newsletters, announcements, legal notices, or policy updates.
The Single Sends API allows you to create, retrieve, update, delete, schedule, and deliver your Single Sends. There are also endpoints for searching and statistics to help you maintain and alter your Single Sends as you learn more and further develop your campaigns.
The Single Sends API changed on May 6, 2020. Please check the SendGrid Knowledge Center for updates and instructions here: https://sendgrid.com/docs/for-developers/sending-email/single-sends-2020-update/