DomainKeys spam protection is enabled at server level and for the domain example.com. However this feature does not work. Is DomainKey supported in Plesk Automation (PA) 11.5?
DomainKey support is implemented in PA since MU 18 according to the Release notes
Please update to the last PA version to enable support for Domain Keys.
NOTE:DKIM (DomainKeys Identified Mail) feature is not implemented in Plesk Automation 11.5 yet.