- Plesk for Windows
- DNS server is Disabled in Plesk > Tools & Settings > Server Components
- Allow signing outgoing mail is not displayed in Plesk > Tools & Settings > Mail Server Settings
- Use DKIM spam protection system to sign outgoing email messages is enabled in Plesk > Subscriptions > example.com > Mail Settings
- DNS server used to be enabled when option Allow signing outgoing mail was enabled
The issue is submitted as a bug #PPPM-8709 which is planned to be fixed in one of the future Plesk updates.
Until the fix is available use the following workaround:
Enable DNS Server at Tools & Settings > Server Components.
Disable option Allow signing outgoing mail at Tools & Settings > Mail Server Settings
Disable DNS Server at Tools & Settings > Server Components.