To register user on platform you have to open website and follow the instructions below:
Click on “Create account” link (registration form will be opened)
Select account type you want to create while register user
Platform supports two types of account, they are personal and company. Personal account fit to small companies who want to use a couple of mailboxes. Company account better fit to big companies who contains big amount of employees
Fill in required details and proceed according to instructions. Detailed instructions.
On platform exist password policy which you can read here.