Real System users

[exy123]

Hey

Question about how ispconfig works with email users and domains. I noticed users created through ispconfig cant use outlook to check thier mail , then i found the post where it was explained you have to have real system users.

Now my question is how to do you tie in the users made through ispconfig and the real system users so that they can check thier mail without login failed errors ?

And also if you have john@domaina.com and you have john@domain-b.com how would the mail for them be seperated if you can only create one system user with the username john ?