Mailpoet: Change column sizes

mailpoet_change_column_sizes.php

<?php
/**
* This will replace the default values with new ones, within the rendered content of newsletters
*/
add_filter( 'mailpoet_rendering_post_process', function ( $content ) {
    $max_width = 900;
    $width_mapping = [
        660 => $max_width,
        330 => abs( $max_width / 2 ),
        220 => abs( $max_width / 3 ),
        440 => abs( $max_width / 3 * 2 )
    ];

    foreach ( $width_mapping as $width => $new_width ) {
        $content = str_replace( "width=\"$width\"", "width=\"$new_width\"", $content );
        $content = str_replace( "width:" . $width . "px", "width:" . $new_width . "px", $content );
        $content = str_replace( "max-width:" . $width . "px", "max-width:" . $new_width . "px", $content );
    }
    return $content;
}, 20, 1 );