You have to find the name of the editor who will read the query. It's usually somewhere in the guidelines. Sometimes the correct name is preceded by "contact", and sometimes it's buried in prose, but it should be there. It's often whoever wrote the guidelines. The problem with sending something to the wrong editor is that the right editor might be working hundreds of miles away. At best, sending to teh wrong editor often means long delays. At worst, it can mean discarded queries.