Detecting existing subscribers

Problem/Motivation

Hi, I'm wondering if this module has the ability to compare the currently logged-in user to the list of subscribers in GovDelivery and prevent the form from showing if they are already subscribed? Maybe it would instead show a link to manage the user's subscriptions or just hide the block all together?

You don't cover this in the module description, so I wanted to ask. My client wants to show the signup form, but also doesn't want to annoy people who have already subscribed.

Thanks :)