How to automate initial mailman configuration via API call?
There is no way to execute initial mailman configuration via API calls. However, it is possible to automate initial mailman server configuration via CLI by executing the command alike:
# LISTPWD=<admin_password> plesk sbin listmng create mailman - <firstname.lastname@example.org> quiet
Values enclosed in
<> should be replaced with actual ones.
Afterward, you will be able to manage mailing lists via XML API. Additional information available in XML API Guide