Sorry, not sure what you mean, do you have multiple emails on your phone, and only want one of them to have notifications or you have one email configured on your phone, but only want one or two peoples emails to alert you?
If you are on exchange, the latter is easy, create a rule to forward all other emails not from that user to another folder, then setup the phone to only sync your inbox and not the new folder, you can still read emails in the new folder, but it won't push them and thus shouldn't notify you.