When I send an email to a list, or BCC myself on something, I don't receive it. Why?

Google Mail recognizes that the incoming message is identical to the copy in your “Sent” and ignores the duplicate. This is a part of Google's threading feature in the web client when you post a reply, your reply is threaded in with other's responses. This is a system feature and cannot be disabled. Sent emails can always be viewed in the “Sent” label.