Messenger error 200: Message Not Sent: person isn't available

Code 200 with subcode 1545041 reads like a permission error, code 200 belongs to the Graph API's permission block, but the subcode tells the real story: 1545041 is the same "this person isn't available right now" condition that surfaces as 551/1545041. The recipient cannot be delivered to: they have blocked the Page or its messages, deactivated their account, or restricted who may message them. Meta's error-codes table lists both codes with near-identical strings, and which one you receive depends on where in the pipeline the check fired, not on anything you can influence.

The practical consequence is that your error handler should classify by subcode here, not by code. A handler that routes all code-200 errors to "App Review problem" will tell your on-call engineer to resubmit for review because one user blocked the Page, a genuinely misleading alert. The review-wall variants (2018028, 2018027) have their own subcodes; 1545041 under any code means the same unreachable-recipient verdict.

As with 551, Meta will not disclose which specific condition applies, there is no reachability check, no appeal, and no retry that helps. The message is not queued for later; it was refused.

{
  "error": {
    "message": "(#200) Message Not Sent: This person isn't available right now.",
    "type": "OAuthException",
    "code": 200,
    "error_subcode": 1545041,
    "fbtrace_id": "BLBz/WZt8dN"
  }
}

Build the unreachable flag into your contact model with an automatic reset on inbound activity, and make every campaign query exclude flagged PSIDs. Keep block rates low by respecting frequency and relevance, the same hygiene that avoids policy blocks. The unreachable-recipient trio (551, 200/1545041, 10/2018108) is contrasted in the Messenger troubleshooting guide.