Im shocked that this still isnt a feature in 2017...
I am shocked that this is nearly 12 months old, and still has not been solved. There absolutely needs to be a way to find certain emails by limiting the folders.
You can set up a rule that will play a sound when you receive email from an account - you can do all accounts inboxes, or you can do different sounds for different accounts. Then, you can disable the sound under the account settings that plays as default.
This was a workaround for me that allows me to get banner notification on my work account, but all personal accounts have notifications turned off, with a custom sound rule established.