Form rejections are part of the business for writers. If you're like me, your instinct will be to chuck the ugly thing in the trash. Instead, take a minute and read through it with a careful eye. There are usually some positives wrapped in these big, fat NOs. I've pasted one of my very own form rejection letters below and highlighted a few inspiring points at the bottom.
Thank you for giving me the opportunity to consider your manuscript.
I'm sorry to say that I do not see a place for your manuscript at XYZ. We receive a very large number of book proposals and manuscript submissions, including many of considerable merit, and of these we are able to publish very few. I regret that this volume also prevents me from replying with individual editorial comments.
Publishing decisions are, of course, influenced by a publishing houses's style and an editor's opinion. Although your work isn't right for XYZ, perhaps it will have a place at another company. I wish you every success in your publishing endeavors.
Positive things of note in this letter:
1. You got a response! Many houses don't even bother anymore if they're not interested, so this is something to be happy about. You can confidently mark this submission 'closed' and not wonder if it got lost in the mail.
2. This publishing house receives "a very large number of...submissions". Sometimes these numbers are in the tens of thousands per year. If your submission was in the top 1%, that would put your manuscript in the top 100...which is great-- unless the company only publishes fifty books a year. Being rejected doesn't mean your book sucks.
3. The point the editor makes about decisions being influenced by a house's style and an editor's opinion is exactly right. Another house and another editor may feel completely different, so get that manuscript out again.*
4. You rock for putting your work out there! It takes time and effort and stainless steel guts to create a query, compile the submission and send it off to be critiqued. And most likely you'll do this many more times than you'd like before finding a home for your book. So give yourself a cookie and be happy knowing you've knocked down one of the rejections on your way to fame, fortune and publishing success.
*I'm a huge advocate of submitting. As I've often quoted, "100% of shots not taken, don't score" so a book that sits in a drawer has zero chance of being published. However, a book that's not ready to send out has the same chances. So does a middle-grade novel sent to Flux, since Flux only publishes YA. So, send out your work, but make sure it's ready first and do your homework to make sure you're sending it to appropriate people. The Children's Writers and Illustrators Market is invaluable for that.