How to setup e-mail for use with Outlouk / Mailclient with Virtualmin

Hello,

I have setup mail.mydomain A and MX records, and added user myname@mydomain.com to virtualmin.

How can I setup mail so that I can use it in Outlouk or any other mail client via IMAP and POP?

I have searched for tutorials, found other questions, but all with differten options. Is there a tutorial or guide on how to set this up?

Also, in my previous hosting experiences it was often possible to use some general mailserver, like mail.thehost.com. Whatever domain I used, I could authenticate on their mail server as long as I created my mail account in their directadmin panel. In my case I do have a simple setup of main and subservers, with 3 simple lightweight sites. Is it possible to have the subservers (as virtualmin calls them) let use the mailserver of the main site? This would spare me lots of time for future domains/mailaccounts.