The vocabulary of inbox-side email monitoring
Plain-English definitions for the concepts that show up when you start watching your email journeys from the inbox instead of the dashboard. No marketing jargon, no internal acronyms, just the terms a marketing ops or CRM lead actually needs.
Core concepts
Start here
Silent send
An email your ESP says it sent but no one received. The most common form of customer-email failure.
Triggered flow
An automated email sequence kicked off by a customer action: signup, purchase, cart abandonment, password reset.
Heartbeat monitoring
Watching for a steady cadence of expected emails, and alerting when the cadence breaks rather than when a single send fails.
Journey Step
Receive-side monitoring for Journey Step email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Email Suppression
Receive-side monitoring for Email Suppression email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Audience Split
Receive-side monitoring for Audience Split email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Webhook Trigger
Receive-side monitoring for Webhook Trigger email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Receive Side Monitoring
Receive-side monitoring for Receive Side Monitoring email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Campaign Vs Flow
Receive-side monitoring for Campaign Vs Flow email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Flow Trigger Failure
Receive-side monitoring for Flow Trigger Failure email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Transactional Email Failure
Receive-side monitoring for Transactional Email Failure email journeys. Catch silent sends, late arrivals, and broken triggered flows from the inbox.
Where to next
Apply the concepts to your platform
Once you know the vocabulary, the platform-specific monitoring guides walk through how each concept maps to flows in Klaviyo, SFMC, HubSpot and other ESPs.
From the blog
These concepts, applied
- CRM journey observability: the umbrella term for what the glossary entries below sit under.
- 25 hours of silence: a worked example of silent send detection in practice.
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