The mailing lists in Plesk can be managed with the maillist utility through CLI. This utility can be used to create/delete mailing lists, add/delete email addresses to the mailing lists, editing email notification settings for the mailing list administrator, enable/disable mailing lists and setting the mailing list status. The following command is used to remove a mailing list from a domain. For example, to remove a mailing list MailList from the domain example.com, use the command
plesk bin maillist --remove MailList -domain example.com
or
plesk bin maillist -r MailList -domain example.com