Adds a pluggable email transport so self-hosters without Azure/M365 can send
mail through any standard SMTP server (Postfix, Gmail, Mailgun, SendGrid, corp
relay). Graph stays the default; behavior is byte-for-byte unchanged when
EMAIL_TRANSPORT is unset or "graph".
- config: EMAIL_TRANSPORT ("graph"|"smtp", default graph) + SMTP_HOST/PORT/
SECURE/USER/PASSWORD/FROM.
- services/email.js: branch by transport behind the SAME public sendEmail()/
isConfigured() surface. SMTP via nodemailer (lazy-required, like MSAL).
Shared across both transports: the "[ScreenTinker] " subject prefix (unless
rawSubject), the GRAPH_DEV_RESTRICT_TO allow-list, html-from-text derivation,
and the never-throws contract (failures log + return sent:false). SMTP_SECURE
true=implicit TLS(465)/false=STARTTLS(587). Auth optional (unauthenticated
relay ok); SMTP_USER without SMTP_PASSWORD is flagged. SMTP_FROM parses
"Name <addr>". New emailConfigStatus() for startup diagnostics.
- server.js: startup logs the transport and a LOUD error when the selected
transport is partially configured (some fields set, others missing) or when
EMAIL_TRANSPORT is invalid (falls back to graph). A fully-unset transport
stays a silent stdout fallback (unchanged dev behavior).
- nodemailer ^6.9.16 added as a production dep (bundled in the Docker image).
- .env.example + README: SMTP config section, Gmail example, transport table.
- test/email-transport.test.js: 15 tests — transport selection, config
validation (missing/partial/invalid), SMTP message building (from/prefix/
fromName override/text alt), sendEmail routing (mocked nodemailer), rawSubject,
dev-restrict on smtp, and the smtp_error never-throws path.
462/462 server tests pass. Boot verified for all four states (configured,
misconfigured, invalid, default).
Closes#173
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
