When you setup mantis to use ldap and use ldap email field instead of mantis db mail attribute, when a user want to setup his information after signup for a new account there is no email field but after validating informations you have an error "Invalid Email"

i have set into core/email_api.php:

    function email_ensure_valid( $p_email ) {
            if ( ON != config_get( 'use_ldap_email' ) ) {
                    if ( !email_is_valid( $p_email ) ) {
                            trigger_error( ERROR_EMAIL_INVALID, ERROR );
                    }
            }
    }

And now it's work fine