Type of issue: (feature suggestion, bug?)

Suggestion

Chapter:

no-chapter

Why use .jsx instead of .js? It's not a best practice: facebook/create-react-app#87 (comment)

It would be better to use bcrypt, beause its more secure as it's slower (uses more computing cycles).
Your code could also be better:

You wouldn't need salt field in User model, because it's saved into the same field as password does.

For authentication, something like:

var mongoose = require('mongoose'),
  bcrypt = require('bcryptjs');

var userSchema = mongoose.Schema({
  email: String,

Problem
As of now, when a user has to configure inbound emails, there are some settings related to this under the account settings page. This is confusing and does not really say anything more about each of the settings.

Solution
Required more documentation on guiding a user to configure this.