Change the default "From" address for Wordpress.

gistfile1.php

<?php

function change_wp_mail_sender( $phpmailer ) {
  $from_name = 'My Website';
  $from_email = get_option('admin_email'); // The same email seen in Settings > General

  if (
    // We should always have these parameters, but it doesn't hurt to avoid errors in the future
    property_exists( $phpmailer, 'From' )
    && property_exists( $phpmailer, 'FromName' )
  ) {
  
    // Check if the from address is the same as default in pluggable.php
    if ( $phpmailer->From == 'wordpress@' . preg_replace('#^www\.#', '', strtolower($_SERVER['SERVER_NAME'])) ) {
      $phpmailer->From = $from_email;
    }
    
    // Check if the from name the same as in pluggable.php
    if ( $phpmailer->FromName == 'WordPress' ) {
      $phpmailer->FromName = $from_name;
    }
    
  }
}
add_action( 'phpmailer_init', 'change_wp_mail_sender' );
// You might also want to use the filters: wp_mail_from, wp_mail_from_name