Inbox message metrics

Updated August 17, 2026

Inbox messages follow similar delivery patterns to regular in-app messages: a message is sent, but it isn’t displayed until the recipient returns to your website or app and opens the inbox.

Unlike other channels, inbox messages aren’t “delivered” in the traditional sense. A message counts as delivered and opened when the recipient opens the inbox and sees it—so the time between sending a message and its open depends on your audience’s behavior.

How these events are reported depends on how you set up your inbox:

Visual inbox: Customer.io renders the inbox and reports opens, clicks, and deletes automatically.
Build your own inbox: you report opens and clicks yourself with the SDK. See report metrics.

flowchart LR a(Send inbox message) a-->b{Is the recipient on your website or app?} b-.->|no, wait until they return|b b-->|yes|c{Did they open the inbox?} c-->|yes|d(Message is displayed and reported as delivered + opened) c-.->|no|e{Is the message expired?} e-->|no, wait for the user to open the inbox|c e-..->|yes|i(Message expires and is removed from the inbox)

Available metrics

Like other in-app messages, inbox messages report the following metrics. The delivered metric is reported together with opened, because an inbox message isn’t “delivered” independently of being seen (as it might be for email).

Metric	Reported when	Description
`sent`	Customer.io sends the message	The message was sent.
`delivered`	The recipient opens the message in the inbox	The message reached the recipient. Reported together with `opened`.
`opened`	The recipient opens the message	The recipient saw the message in their inbox.
`clicked`	The recipient clicks a link or button	The recipient clicked the message.
`failed`	Customer.io can’t send the message	We couldn’t send the message—typically a liquid rendering issue.