Real-time SMS forwarding

When SMS arrives at one of your SIMRelay numbers, the message hits our system, gets validated and recorded, and is dispatched to every configured recipient within seconds. The forwarding engine is the core of what we do.

Delivery channels

You can deliver each incoming message to any combination of:

• Email — to one or more addresses, with the original sender and timestamp preserved.
• Slack — into a specific channel, with per-channel routing rules.
• Microsoft Teams — into a channel via Incoming Webhook.
• Webhooks — HMAC-signed POST to any HTTPS endpoint you control.
• WebSocket — real-time push to the SIMRelay dashboard if a teammate is logged in.
• SMS forwarding — relay the message to one or more recipient phone numbers (subject to plan).

How fast is "real time"?

From the carrier's delivery to the first downstream notification is typically under a second. Slack and Teams delivery depends on their ingestion latency, which is usually under three seconds. Webhook delivery is async with retries on failure: we retry with exponential backoff for up to 24 hours and surface the full delivery history in the dashboard.

Filtering and routing

You can route differently per number, per team, or based on message content. A "no-code-please" filter pattern, for example, will skip forwarding any message that doesn't look like a verification code. Routing rules are evaluated server-side, so even if you've configured five recipients, an unmatched message only fans out to the ones whose rules permit it.

Reliability

The forwarding queue is durable. If a downstream destination (Slack, your webhook endpoint, your email server) is unavailable, the message stays queued until delivery succeeds or the retry budget is exhausted. Failures are visible per-destination in the audit log so you can spot a misconfigured webhook before it costs you a code.