A failed post is a message, not just a mark. "Target gone" means fix the list. "Not signed in" means fix the session. "Platform refused" means the post or the pace broke a rule. Three reasons, three different repairs, and none of them is "try again".
Make it a habit: no retry until the reason has been read and the cause fixed. A queue will repeat a mistake at scale if you let it, and a platform watching the same failure arrive five times draws its own conclusions.