CPT Post Title Permalink: Replace “@” (or all special characters) with dash “-” instead of just removing

Question

Just make sure your filter runs before the one that WordPress itself applies – add a priority of 9:

add_filter( 'sanitize_title', function( $title ) {

    if ( FALSE !== strpos( $title, '@' ) ) {
        $title = str_replace( '@', '-', $title );
    }

    return $title;

}, 9 );

Usage:

echo sanitize_title( '[email protected]' );

Output:

mytitle-example-org