Creating domain alias is failing with the error below:
PHP Warning: array_merge() [function.array-merge]: Argument #2 is not an array
#0 Smb_Exception_Syntax::handleError(2, array_merge() [function.array-merge]: Argument #2 is not an array, /opt/psa/admin/plib/spamfilter/GreyListManager.php, 70, Array ([action] = disable-greylisting,[data] = Array ( = flashback-production.de),[stdInList] = Array (),[domainNames] = domain.tld))
#1 array_merge(Array (), example.com) called at [/opt/psa/admin/plib/spamfilter/GreyListManager.php:70]
#2 GreyListManager-_processDomainBatch(disable-greylisting, Array ( = example.com)) called at [/opt/psa/admin/plib/spamfilter/GreyListManager.php:43]
Grey listing spam protection is not enabled.
This is Plesk internal issue with ID #PPPM-759 which was fixed in Plesk 12.0.18 MU#6
Enable the "Switch on greylisting spam protection for all mail accounts under this domain" option from the mail settings of the domain.