- Plesk for Linux
- Plesk Obsidian is installed on the server
- The Mail autodiscover option is not shown in Tools & Settings > Mail Server Settings.
- Plesk Premium Email extension is installed.
Plesk Premium Email disables Plesk autodiscovery globally in server settings.
This is the expected behavior when the Plesk Premium mail extension is installed on the server because it has its own autodiscover.
This has been reported as bug ID PPPM-11874 which will be fixed in future updates.
If it is required to use Plesk's autodiscover, remove the line
autoconfig.enabled = 0 under the section