4005: Recipient does not support this message type

HTTP status: 422.

The recipient cannot receive this message type. iMessage app messages require the recipient to be reachable over iMessage and do not fall back to SMS/RCS. This is an HTTP 422 error, delivered asynchronously as a message.failed webhook.

• Confirm the recipient is iMessage-capable before sending app messages — see the iMessage capability check
• Or send a standard text or media message, which can fall back to SMS/RCS

• iMessage Apps
• Webhook Events
• Error Codes