Claude Fable 5.1 & GPT-6 Astra packages are live

email

Backend

Sending transactional email that arrives — SPF/DKIM/DMARC, provider choice, templating, bounce handling, and keeping the sending domain reputable.

Choose your model

Available for 11 model families. The engineering substance is the same in each; the structure, checklist phrasing and constraint ordering are tuned per family.