The only major publisher I’m aware of that continues to consider unsolicited material for its imprints is Kensington, which is not categorized as a Big 5 publisher because it remains independent and not part of a conglomerate. Regardless, Kensington has imprints covering a dozen or more genres, and subscribers can query any of them if their material fits. But make certain it’s an “exact match,” or I can attest from personal experience that the outcome will be frustrating. I’ve written two stories for Pinnacle, the firm’s Thriller imprint, and I missed on the criteria in both cases and was never able to massage the plot elements in a way that would be acceptable.
And the editor in chief of Kensington had personally edited an early manuscript of mine, and she continues to take my phone calls on a very friendly basis, so I can’t stress enough the importance of genre specificity, as it also varies from one publishing company to another. Meaning, a Thriller perfectly matching the guidelines for one might not pass muster with another. This is the reason it’s so very important to read what a publisher is putting out there in the genre in which material is written.
I can guarantee that any writer doing this will have a much better shot than going at it based solely on his or her idea of genre. As everyone knows all too well who has tried to become published by a major royalty publisher, it’s an immensely complicated process. What I’m suggesting can smooth out the bumps somewhat, in that a writer will be presenting a book that will at least fit a respective publisher’s guidelines. Then it’s down to likes or dislikes, which it the way it should be, and not that the book didn’t replicate that imprint’s model.