I've released Upyo 0.6.0, an email library for JavaScript and TypeScript that works across Node.js, Deno, Bun, and edge runtimes. This version adds MIME composition without sending, streaming attachments over SMTP, and calendar invitations. You can also set message identifiers for tracking replies and check SMTP or JMAP configuration without sending a test email. There are new Maileroo and Mailtrap transports, plus a LogTape integration for logging delivery or trying out email workflows locally. https://github.com/dahlia/upyo/discussions/75