How can I find out which of our 7 verified email addresses are actively used by our customers?

[schwitzen-com]

How can I find out which of our 7 verified email addresses are actively used by our customers?

We have configured 7 of them, but some of them are probably no longer in use, which we need to check before removing them.

In all of our webshops and marketplaces, it is almost impossible for us to see where we have offered which address for customer payments.