What happens to your message when the network fails
Updated 11 July 2026
Throttled Wi-Fi, a captive portal, 2G in a dead zone, a firewall that blocks half your traffic — here is exactly what Sendant does with your message, step by step, and where it is honest about its limits.
Short answer: your message is encrypted on your device first, so it never travels as readable text. If it can't be delivered right away — the network is degraded, or your contact is offline — it waits as encrypted ciphertext in a store-and-forward mailbox and delivers the moment a device reconnects. You and your contact never have to be online at the same time. Sendant is built for throttled, restricted, or intermittent networks, not total blackouts — it is not a Bluetooth mesh app.
The delivery ladder
Getting a message from one device to another is not one path — it's a series of fallbacks. Here is the ladder Sendant follows, and we're explicit about which rungs ship today and which are on the roadmap.
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Encrypt on the deviceShips today
Before anything touches the network, the message is end-to-end encrypted on your device using X3DH and the Double Ratchet — the same cryptographic primitives Signal uses. Whatever happens next, only the recipient can read it. The server only ever handles an encrypted envelope.
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Deliver through the encrypted mailboxShips today
Today Sendant delivers through an encrypted store-and-forward mailbox. If your contact is offline or your connection is flaky, the ciphertext waits in the mailbox and is delivered when their device next connects. Small encrypted payloads survive slow, lossy links far better than a live session that needs both parties connected at once — which is why intermittent and throttled networks are Sendant's honest home turf.
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Direct peer-to-peerOn the roadmap
A planned path lets two devices exchange messages directly when a route between them exists, reducing reliance on any single server. This is roadmap, not a shipped feature — we won't claim it works until it does.
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Relay when direct won't connectOn the roadmap
When a direct path is blocked by NAT or a restrictive firewall, a relay can forward the still-encrypted envelope. (Sendant already runs relay infrastructure for encrypted voice calls; extending relayed paths to message delivery is on the roadmap.)
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Local networkOn the roadmap
On a shared local network — a venue Wi-Fi, an office LAN — devices could reach each other without the public internet at all. Roadmap. This is not the same as radio mesh: it needs a common network, not Bluetooth between phones.
Why this matters for privacy, not just uptime
The two properties reinforce each other. Because delivery is store-and-forward with content encrypted end to end, the server can hold a message for a disconnected recipient without ever being able to read it — it stores an envelope, not text. And because you don't need a live, simultaneous connection, Sendant stays usable exactly where surveillance and censorship pressure are highest: on captive portals, behind DPI firewalls, on the metered 2G you fall back to when the good network is gone.
What we deliberately don't claim
This niche fact-checks hard, so the bounds matter. Sendant is not a mesh messenger, does not "work without internet," and is not yet independently audited. It is an early messenger built on well-understood primitives, honest about which delivery paths ship today (encrypted mailbox) and which are still roadmap (peer-to-peer, relay, local network). If you catch us overstating any of this, tell us — we'll fix it.
Try it on a bad network right now
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