- API: Specify
stream_typein request body ormetadata - SMTP: Add
X-Stream-Typeheader to your email (see SMTP section) - Automatic Selection: If not specified, the default depends on the channel:
POST /senddefaults totransactionalPOST /bulk-senddefaults tobroadcast- SMTP defaults to
shared
The system automatically optimizes delivery for each stream type to ensure the best inbox placement and deliverability for your emails.