//219purge_sentmail_keep
// when purging sent-mail folder, purge messages older than how many days?
$_prefs['purge_sentmail_keep'] = array(
    'value' => 30,
    'locked' => false,
    'shared' => false,
    'type' => 'number',
    'desc' => _("Purge messages in sent-mail folder(s) older than this amount of days."),
    'help' => 'prefs-purge_sentmail_keep');
    
