Nodejs/mongo app - parsing excel and validating emails

I would like a SaaS app that will let people signup for service (no ecomm right now) it will send an email to the admin to confirm the person can join the system. We will be lettings users upload excel sheets to the system with user contact info the sheet. it will look like First name, last name, company, url, email address we will not always have email address given to us, here is where the fun begins. we will take the name and url from the company and try to guess what the email might be for example [login to view URL] jdoe johnd etc... we will need some easy to manage config for different guesses in the future we will then throw these contact emails to a 3rd party api to try and figure out what email might be the right one. [login to view URL] something like these guys, they will return back a score and some data which we will use to give back to our users. we should maintain a database in mongo of domains and the pattern that seemed to work for them in the past, future uploads can guess this format so we don't need to iterate over a lot of matches all for the same company. if the email was provided in the excel we will validate it as a normal api request. the user output should be an excel sheet with the outcomes and best guess emails for the missing versions. the markup for the admin will be bootstrap and we will use an admin theme from themeforest. The system should track what the user has uploaded and the outcome of each "job" in the past, we will also need ot see on the admin side a list of users and the requests they have made since each request to the 3rd party api will cost us something, we will need to know numbers so we can track offline billing . let me know questions and estimates on time and cost.