Disable WordPress auto-update emails (plugins/themes/core)

// Disable auto-update emails.

add_filter( 'auto_core_update_send_email', '__return_false' );

// Disable auto-update emails for plugins.

add_filter( 'auto_plugin_update_send_email', '__return_false' );

// Disable auto-update emails for themes.

add_filter( 'auto_theme_update_send_email', '__return_false' );