Spring Boot is the leading Java framework for enterprise backends. Its Spring Framework mail abstraction (MailSender / JavaMailSender) supports SMTP out of the box via spring-boot-starter-mail, with provider-specific starters layered on top the same way Rails delivery methods and Laravel mail drivers work.
Install mailkite-spring-boot-starter and set mailkite.api-key for a native JavaMailSender bean — or just point spring.mail.host at smtp.mailkite.dev. See /docs/integrations/spring-boot.
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=Spring Boot Point a domain, set one SMTP endpoint, send your first email in minutes. Unlimited domains, no credit card.