The use of the inbox for error messages is problematical, to put it politely. When you crosspost, you get a message in your inbox. When you cross post every time you post, your inbox fills up. I write a blog post every day, and have done for several years now, so my inbox is full of these redundant messages and as a result is completely and utterly useless for anything else. I'm effectivaly spamming myself, because DW doesn't give an option to switch off those successful messages. Until that's fixed, I might as well assume that DreamWidth doesn't provide any kind of inbox service. That's a pain.