Adding new content filters breaks header_checks, body_checks etc.
openSuse 11.4 x64:
Adding new content filters under Email -> Global Filters (Content Filter) renders the corresponding /etc/postfix/header_checks ...body_checks etc. inoperable, due to a false line break being inserted between the reg exp-pattern and the action.
This can be resolved by replacing the following code in the file /usr/local/ispconfig/server/plugins-available/postfix_filter_plugin.inc.php:
$content .= $rule["pattern"]."\n";
$content .= $rule["pattern"];