Project Hera
The mail engine of Lindeier.at — every message received, signed, sealed, and delivered.
Project Hera is the mail server infrastructure of Lindeier.at. Named after the queen of the Olympian gods — the deity of bonds and binding — Hera is the layer that connects this platform to the rest of the world: it receives mail addressed to @lindeier.at, sends mail on behalf of its members, and stores every message encrypted on this server.
Hera is deliberately invisible. It has no user interface of its own — it is pure infrastructure, spoken to over the standard mail protocols (SMTP and IMAP) by ordinary mail clients today, and by Project Alexandria, the platform's own webmail client, in the future. Live since June 2026.
When someone, anywhere in the world, sends a message to an @lindeier.at address, this is what happens — in well under one second:
Outbound mail makes the same journey in reverse — and leaves carrying a cryptographic signature that proves to the receiving server it genuinely came from here.
Email is one of the oldest and most unforgiving systems on the internet — a place where reinventing wheels gets your mail silently discarded. Hera therefore takes the opposite approach to most Lindeier.at projects: instead of building from scratch, it is assembled from the most battle-tested open-source mail software in existence — Postfix for transport, Dovecot for storage, rspamd for filtering and signing.
The ownership lies not in the code but in the configuration: every record, every restriction, every key on this server was set deliberately and is documented completely. No managed service, no third-party provider, no black box. The mail lives here, under full control — and nowhere else.
Postfix handles SMTP transport: receiving mail from the internet on port 25 and sending authenticated member mail out into the world. Dovecot stores mailboxes and serves them over IMAP, encrypting every message at rest with its mail-crypt engine. rspamd sits in the middle of both directions — scoring inbound mail for spam and signing outbound mail with DKIM.
Identity is not Hera's job. Accounts live in the Shambala user database, and Hera simply asks it questions: does this recipient exist? when mail arrives, and is this password correct? when a member logs in. Creating a Lindeier.at account is creating a mailbox — there is no second registration, no separate password, no provisioning step. One identity, everywhere.
Mail from this domain is fully authenticated: SPF declares which server may send for lindeier.at, DKIM signs every outgoing message, and DMARC tells the world what to do with mail that fails those checks. This is what Gmail reports when it receives a message from Hera:
On disk, mailboxes are ciphertext. This is what a stored message actually looks like on the server's filesystem — the readable text exists only in transit to its owner:
Around the core: TLS is mandatory on every connection, an MTA-STS policy tells other providers to refuse unencrypted delivery, and Fail2ban automatically bans hosts that probe the server with failed logins.
Hera is live and fully operational — sending, receiving, signing, filtering, and encrypting since June 2026. Members use it today with any standard mail client; the settings are below. The next chapter is Project Alexandria: a webmail interface built on top of Hera, so that @lindeier.at mail can be read and written directly in the browser.
Every Lindeier.at member account is a mailbox: username@lindeier.at, with the same password used to log in here. Any mail client works: