One of the writers I work closely with, his first time getting an acceptance ever came from a major pro publication backed by a well-known editor. He didn't realize his story was technically a reprint, because it had already been published online. When he mentioned this to the editor--*weeks *after the contract was signed and after two rounds of edits were done--the guy pulled his deal, because it's a contract violation. He sent the writer a very straightforward email, and he ended up blacklisted. So, always ask before submitting.