Advanced settings of mailing lists were lost after transfer (migration) in Parallels Plesk Panel.
Migration & Transfer Manager transfers only basic settings of mailing lists: list administrator, subscribers and mailing list archives. Other settings are not transferred, since Plesk cannot manage them.
It is possible to transfer configuration of mailing list using Mailman's native utilities. Below example shows how to transfer settings of maillist
maillist1 from one server to another:
On source server save mailing list configuration into file:
/usr/lib/mailman/bin/config_list -o maillist1.conf maillist1
maillist1.confto destination server, where domain with mailing list has already been transferred and deployed, and restore configuration:
/usr/lib/mailman/bin/config_list -i maillist1.conf maillist1