FastAPI is a modern async Python framework. Email uses aiosmtplib for async SMTP or ESP async SDKs.
Call the MailKite Python SDK from a runnable starter app — wrapped in run_in_threadpool so it doesn't block the event loop — or point aiosmtplib at MailKite's SMTP endpoint. See /docs/integrations/fastapi.
Read the full setup guideA minimal, copy-paste starter. Swap in your own domain and API key.
# Any app that accepts an SMTP server works with MailKite
MAIL_HOST=smtp.mailkite.dev
MAIL_PORT=587 # STARTTLS (or 465 for TLS)
MAIL_ENCRYPTION=tls
MAIL_USERNAME=mailkite # username is ignored
MAIL_PASSWORD=mk_live_... # your MailKite API key
MAIL_FROM_ADDRESS=you@yourdomain.com # on a verified domain
MAIL_FROM_NAME=FastAPIPoint a domain, set one SMTP endpoint, send your first email in minutes. Unlimited domains, no credit card.