[Auth] Enable spam user filtering of emails on the free tier

[fredteumer]

Objective

Enable spam filtering of emails on the free tier

Origin Document

We have seen users sign up using regex abuse to create hundreds of users on our free tier and cycling through their limit cap instead of paying for the service.

Goals

• Eliminate all abusers of the free tier through repetitive email signup or symbol abuse
• Perform a cleanup of the Portal DB users to eliminate spammers

Deliverables

• Regex filter in the Auth Provider to filter out
• Audit of the Portal DB user set
• Removal of repetitive users in the database

Non-goals / Non-deliverables

• Implementation of Captcha or other similar software
• Any additional bot protection

Creator: @fredteumer