Our team here are publishing pages with a page properties macro that has the following table:

We want to send an email that uses information from within the page properties table.
I have seen mention of creating a variable with {{page.body.storage...}}
I thought this might work:
{{page.body.storage.substringBetween("CCustomer Affected","")}}
But I dont understand what it's doing and I cannot for the life of me find anything that explains it.
Is it even possible to fill an email that is sent with a confluence automation on publication of a page that contains the information that has been entered in the Page properties table?
Thanks for your help.