There can be instances when the Mailing List Manager in Plesk is not displayed in the Tools & Settings option even after this feature is installed in Plesk. Below are the steps to enable the same in Plesk CLI:
[root@domain~]# /usr/local/psa/bin/maillist –update-service domain.com -status enabled
Mailing list support is not installed or not properly configured.
[root@domain~]# /usr/local/psa/bin/admin –update -manage_server_maillist true
SUCCESS: Administrator’s preferences are successfully updated
You can now update the mailing list admin email id and password and enable the support for Mailing list for your domains