SymptomsParallels Plesk Panel is assigned to Centralized Mail server through Parallels Plesk Expand.
Several mail accounts are shown as problem ones on page Centralized Mail. These accounts have status Limits exceeded and the error below is shown in Synchronization logs.
MySQL databases quota: requested - 0, currently used - 7422438
CauseThe problem may occur after objects migration between Plesk servers or when Parallels Plesk Panel Windows is assigned to Centralized Mail that is actually Parallels Plesk Panel Unix.
By design when Parallels Plesk Panel is assigned to Centralized Mail all domains with whole data are migrated to Centralized Mail server. During migration limits and databases are migrated.
There is a domain limit MySQL databases quota in Parallels Plesk Panel Windows that is missing in Parallels Plesk Panel Unix. And so Parallels Plesk Expand sets the limit to 0 for migrated domains.
The error may happen if domains have databases on Parallels Plesk Panel Windows.
During assignment/migration the databases and limits were migrated to Parallels Plesk Panel Unix.
ResolutionYou should delete databases for migrated domains on Centralized Mail server and run statistics.
Then synchronize problem mail accounts in Parallels Plesk Expand.
The problem will be fixed in future version of Parallels Plesk Expand.
During assignment databases will be removed from Centralized Mail server after completed migration.