Requirements

Compatible distributions

• Debian and RedHat (CentOS) based distro should work OK.
  Checks are made for apache config files locations anyways, so you'll know soon enough if it's not compatible.

Server configuration

• You hostname must be a valid domain name which means it has to respond to ping with your main server IP.
• Your IP's reverse DNS must be valid as well and return your (main) public IP associated with your hostname.

Plesk configuration

• You need to have set an SSL/TLS certificate set as default, used the Plesk panel and for the mail server (by chance, this is easily achieved with Let's Encrypt and Plesk 17 or greater).
• All of your domains need to use the same IP for the mail server (this is default).
• Your Plesk default domain must be set to "None" (this is default) This setting is found in Plesk's IP settings.
• For Outlook autoconfig, each domain needs to be HTTPS accessible with a valid certificate.

DNS configuration

• If you are not comfortable with DNS zones, then your DNS zones shall preferably be managed into Plesk.
  Otherwise, for Thunderbird autoconfig to work, you just need to add the following entry to your domain names' DNS zones: autoconfig CNAME [hostname].tld.