Install claws-mail-perl-filter by entering the following commands in the terminal:
sudo apt update sudo apt install claws-mail-perl-filter
Message filtering plugin using perl for Claws Mail
This plugin enables filtering of Claws Mail messages using perl regular expressions and, in fact, giving all the perl features and power to the filtering engine. . A tool for converting the current filter set of the user into a equivalent perl script suitable for the plugin is also provided.