frm_email_value hook is depreciated

I am trying to change a field value in the email notification.

I have a field that is pulling post meta [post_meta key=whatever] into a hidden field, but the value is a serialized array. I want take the array values and format them into html and add the html into the email notification.

I have tried to use the frm_email_value hook, but I can not get it to work. It looks like the hook is depreciated and there is no documentation for the replacement. hook. I have tried to print out $value, $meta, $entry, but they come back blank.

Another approach I tried was to add a shortcode instead of [post_meta key=whatever], but the post ID is not available so i can't pull the serialized array and return the html I am looking for.

How does the replacement hook for frm_email_value work or how can I get the post ID from an ajax form so I can populate the field get_post_meta( POST_ID_THE FRM_IS DISPLAYED_ON, '', true ) via the output from a shortcode?

I am looking you to give me a total coded solution. I just need to know how to deal with a serialized array from [post_meta] or get the post ID or to get frm_email_value to work.