An internal application uses http to establishes a connection, when content filtering is used in UTM this application does not work correctly, however when we removed http on the policy it works correctly.

We would like to know the reason for the block.

When we had http under applications match for rule_CF the internal application does not work correctly.

content-filtering {
                rule-set Rule1 {
                    rule rule_CF {
                        match {
                            applications [ ftp http imap pop3 smtp ];
                            direction any;
                            file-types reg;
                        }
                        then {
                            action block;
                            notification {
                                log;
                                endpoint {
                                    type message;
                                    notify-mail-sender;
                                    custom-message "Blocked content, contact your administrator";
                                }

We conclude that this is a expected behavior, when using the HTTP protocol in the content filtering policy and as per the policy is set as block, all the HTTP content will be blocked but not the connection.