Block spam & manage SMS blocklist

Overview

Signals includes SMS spam protection that lets you block unwanted senders. Blocked numbers are silently filtered—their messages don't create leads, trigger AI processing, or consume signals.

The system uses a fail-open design: if the blocklist is temporarily unavailable, messages are allowed through rather than dropped. This ensures legitimate messages are never accidentally blocked.

Block a number from a conversation

The quickest way to block a sender:

1. Open the conversation thread
2. Click the Block button in the thread header
3. A confirmation dialog appears—confirm to block

The number is added to your blocklist immediately. A STOP reply is sent automatically (you can disable this in the blocklist settings).

Note: Blocking requires the Manager role or above.

Manage the blocklist

Go to AI & Automation → Routing Rules → SMS Filters to view and manage your full blocklist.

The list shows:

• Phone number
• Who blocked it
• Date added
• Optional notes

Add a number manually

1. Click Add on the SMS Filters page
2. Enter the phone number (E.164 format like +15551234567, or a standard US number)
3. Optionally add a note explaining why you're blocking this number
4. Click Save

You can also block short codes (5–6 digit numbers) to prevent automated marketing messages.

Remove a number from the blocklist

Click the delete icon next to any entry. The number is unblocked immediately, and future messages from that number will flow through the pipeline normally.

STOP reply behavior

When you block a number, the system can automatically send a STOP reply. This tells the carrier to suppress further delivery from that sender.

The STOP reply toggle is on by default. To change it:

1. Go to SMS Filters settings
2. Toggle Send STOP reply on or off

Note: STOP replies are not sent to short codes to prevent automated reply loops.

What happens to blocked messages

• No lead is created
• No AI processing runs
• No signals are consumed (no billing impact)
• The message is silently dropped
• Blocked messages are logged for audit purposes

Tips

• Block from the conversation thread for speed. The Block button is the fastest way to deal with spam in real time.
• Review the blocklist periodically. Numbers blocked months ago may no longer be spam sources.
• Leave STOP replies enabled. This provides carrier-level blocking in addition to the application-level blocklist.
• Fail-open is intentional. In the rare event the blocklist is unavailable, messages pass through rather than being dropped. This is a safety measure to protect legitimate patient and client communications.