https://wordpress.org/plugins/email-address-encoder/

ACF (Email Address Encoder - Plugin ).php

//Add to functions.php
//https://wordpress.org/plugins/email-address-encoder/

//*****************************************************************************
// Email Address Encoder - ACF fields
//*****************************************************************************

//You cannot use Firebug, Web Inspector or Dragonfly, because they decode decimal/hexadecimal entities into plain text. To make sure email addresses are encoded, right-/secondary-click the page, click “View Source”, “View Page Source” or “Source” and search for any plain text email addresses. In Firefox, be sure to test with “View Source” not “View Selection Source”.

add_filter('acf/load_value', 'eae_encode_emails');