Unverified: this entire section describes the intended use case for call tracking numbers (attribution), not a confirmed automated "call data triggers a mail send" capability. No code was found that ingests CallTrackingMetrics call logs, recordings, or conversion events back into LettrLabs to automatically trigger or launch a direct mail campaign. Treat the guidance below as best-practice usage of the number-provisioning and forwarding feature that does exist, and verify with the product team whether any automated trigger capability is planned or already shipped elsewhere before publishing.
What Call Tracking gives you today
Each call-tracking number you purchase is a dedicated phone number you control. You choose which real number it forwards to, and you can assign a distinct tracking number per campaign. Because the number is unique to that campaign, any call that comes in on it can reasonably be attributed to the mail piece that displayed it.
Recommended workflow
Purchase a dedicated number per campaign. Rather than reusing one tracking number across all mailers, buy a separate number for each campaign (or campaign variant) you want to measure independently.
Set the forwarding number. Point the tracking number at the phone line your team actually answers, so no calls are missed while you're tracking response.
Include the tracking number on the mail piece. Use the tracking number as the call-to-action phone number printed on that campaign's design, in place of your main business line.
Monitor call volume as a response signal. Since the number is dedicated to one campaign, a spike in inbound calls after a mail drop is a direct signal of that campaign's performance.
Using call response to inform future mail decisions
Because call volume on a dedicated tracking number reflects response to a specific mailer, you can use that signal manually today to inform decisions such as:
Whether to repeat or scale a campaign that generated strong call volume.
Which offer, design, or targeting list is worth testing again.
Which recipients called in, if you want to follow up with a related mail touch (for example, a thank-you or reminder piece) based on your own records of who called.
Note: automatically triggering a new mail send in direct response to an inbound call event (e.g., a real-time webhook-driven "call happened, so send a postcard" workflow) was not found implemented in the codebase reviewed for this article. If this capability exists or is planned, this section should be rewritten to document the actual automated trigger before publishing.