- Invitations: each user can invite two friends by email (sign-up works
through the link even while registration is closed); admin-editable
template, subject and sender.
- Invitation sender defaults to the system-mail From address, which the
SMTP account is allowed to send as (was postmaster@APP_DOMAIN, refused
with 553 when the two differ).
- Sign-in, sign-up and forgot-password fields show the fixed
@domain after the typed name; the registration status reports it.
- System mail gets a Date header; the invitation's plain-text part keeps
its paragraphs and line breaks.
- SMTP EHLO uses SMTP_HELO_NAME / APP_DOMAIN, not the container name.
- DNS recommendations for the mail domains.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Security (ultimo-security-report.md):
- Security headers on every response, the app shell included: they lived at
server level and nginx dropped them in any location with its own header.
CSP, framing, nosniff, referrer, permissions (docker/nginx-security.conf).
- Plain HTTP forwarded by the reverse proxy is redirected to HTTPS; HSTS on
HTTPS responses. server_tokens off.
- Cross-site state-changing /api requests refused (login CSRF), WebSocket too.
- Validation errors in the usual error shape, without the request model.
- New-password policy: max 128, common/own-address/repeated refused,
breached-password check (HIBP k-anonymity, fails open).
- Message HTML: links keep only http(s)/mailto (sanitizer v6); the HTML
endpoint carries its own no-script CSP.
- Outbound fetches pinned to the checked IP (DNS rebinding); external
IMAP/SMTP servers re-checked before each connection; CGNAT and mapped
addresses counted as non-public.
Fixes from testing:
- IDLE loop catches up before idling: mail that came while the worker was
away no longer waits up to 10 minutes.
- Restore from Spam/Trash/Archive moves only the removed messages, not your
reply in Sent.
- Narrow desktop list stacks sender/subject/snippet (subject was squeezed
to nothing at the default width), with hover actions.
- Phone: wide emails scale to fit the screen.
- Singular forms ("1 message"); no zip button for a single attachment;
app passwords no longer claim "never used" for mail apps.
- ruff format across the backend.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>