acf has a simple shortcode that can be used in the content area in WP that is documented here http://www.advancedcustomfields.com/resources/shortcode/
Basically it would be something like this when editing in text mode, but to be honest I don’t know if this will work with the changes that WP has recently made to the way shortcodes work. You’d have to try it.
<a href='mailto:[acf field="field_name"]'>E-Mail</a>
I’m not familiar with the Divi and don’t know if it will work there.
