When a publisher says he 'does not accept a manuscript' he's telling you, quite politely, he's not interested in publishing any of your works, for whatever reason. Probably 'submissions' would have been the word NG shoulda used, but since it's a 'book', 'manuscript' is rather appropriate in their lingo. I'd advise not to get smart with a publisher, or he won't take you in the least bit seriously.
In order for any of the big fishes to consider you, they have to know you or know about you (i.e. seen your work around). Publishers are in the business to make money: with every book they publish they are taking a big chance, and they want as much assurance as can be had that they will not only recover their investment, but will turn a profit. Being considered by a smaller publisher might even be harder, as they actually stand a higher risk of going bankrupt if one of their projects fails.
I'd suggest sending submissions to magazines for starters, maybe even as a volunteer collaborator. Which magazines, well, that depends on your area of photographic specialty: if you shoot landscapes, try Outdoor Photography, for example. Even so, you need to start local. Look up any magazines in your city and see if they need a photographer or accept submissions. Sometimes they advertise in the jobs online classifieds, looking for photographers. They pay a pittance, but as long as you maintain the copyright of your images, it might not be a bad place to start. Do the assignments and your work will get around; you'll earn experience in the process, not only photographical, but in the area of dealing with clients as well.
. If you're interested in checking out prints for sell of my work go 
