deletion of client do not remove mailinglists
If you delete clients with existing mailinglist(s), this will not be deleted by client_del.php. In line 84 and 135 there are all tables defined, which will be removed in further jobs. The table mail_mailinglist is missing, which will results in unassigned mailinglists.
It is simple to add the table: /usr/local/ispconfig/interface/web/client/client_del.php $tables = 'cron,client,dns_rr,dns_soa,dns_slave,ftp_user,mail_access,mail_content_filter,mail_domain,mail_forwarding,mail_get,mail_user,mail_user_filter,shell_user,spamfilter_users,support_message,web_database,web_database_user,web_domain,mail_mailinglist';
Tested version is 3.0.5.4.