Just an FYI post.
I save all my added Squirrelmail plugins in
/Users/Shared/squirrelmail_plugins/. Consequently if I need to reinstall any or all of them all I have to do is issue the following…
sudo cp -R /Users/Shared/squirrelmail_plugins/PLUGIN_FOLDER /usr/share/squirrelmail/plugins sudo /usr/share/squirrelmail/config/conf.pl
Activate the plugins, save, quit and you’re good to go.