Sometimes, the Plesk’s mail server configuration can become corrupt, for
example, after Plesk upgrade, and it is necessary to restore it. The
restoration is carried out by the internal mchk utility, which is
intended for usage by Plesk. However, as the administrator, you can use
it for repairing the mail server configuration.
By default, mchk runs in the background mode. To execute it in the
foreground, use the -v option. For example:
/usr/local/psa/admin/sbin/mchk -v
Note: You may not wish to restore SpamAssassin settings for mail accounts,
because it requires Perl interpreter to be run. To speed up the
restore process, use the --without-spam option.