Send an email

Sends an email to one or more contacts identified by their email address ("to" accepts a single email or an array of up to 20), from one of the account verified email channels. Use a saved template ("template_id" or "template_name", plus "variables") or free-form content ("subject" and "html_body"). If no contact exists for a recipient address, one is created. When the account has more than one verified channel, "from" is required to pick the sender address. Single-recipient sends also accept "cc" and "bcc" (up to 10 each): one message is sent where cc recipients are visible to everyone. Multi-recipient "to" arrays instead send an individual private copy per recipient. The response contains a per-recipient result list; "success" is true only when every recipient succeeded.