Assuming you are submitting directly to a publishing house without an agent here are some useful guidelines to consider. 

• If you don’t here back from them, they don’t want it.
• Just in case though, check the house website, they usually list the time frame you can expect a response and what it means if you don’t hear back, ie they are running behind or it’s a no.
• Follow the guidelines carefully for the big items like Genre, length, exclusions. But if you need 1 1/4 pages for synopsis and it says one page, go ahead and use the extra 1/4.
• Do your homework. Publishers are not robotic rejection machines. They are humans and will get offended too.
• Sending something in for consideration below the minimum word count threshold is a deal breaker, for one editor on the panel.

-Why Editors Pass Panel