Claws Mail extra plugins are plugins which are not included in the Claws
Mail source package.

This package is a meta-package which requires all those plugins:
claws-mail-acpi-plugin
claws-mail-att_remover-plugin
claws-mail-bsfilter-plugin
claws-mail-fancy-plugin
claws-mail-fetchinfo-plugin
claws-mail-mailmbox-plugin
claws-mail-notification-plugin
claws-mail-pdf_viewer-plugin
claws-mail-perl-plugin
claws-mail-python-plugin
claws-mail-rssyl-plugin
claws-mail-vcalendar-plugin
claws-mail-gtkhtml2_viewer-plugin
claws-mail-attachwarner-plugin
claws-mail-spam_report-plugin
claws-mail-tnef_parse-plugin
claws-mail-address_keeper-plugin
claws-mail-clamd-plugin