Not quite exactly. Adobe Analytics is relying on Adobe Experience Cloud to manage user accounts and profiles. There is no direct API on Adobe Analytics to query the last access of users, but there is a deeper Usage API, Usage API (adobe.com), to get more details usage and access logs. This is an interesting API and I am looking for some use cases on that as well. If using the API, you will need to iterate months back to get the full picture and better store them locally to build your inventory so there is no need to look back into history using API every time.
However, back to your request that API could be a bit overkilled and too complicated. You can manually get the list of Adobe Analytics user and their last access timestamp from the "Admin" menu then "Analytics users & assets", where you can select all to down as CSV. Of course, there is no way from either the API or downloaded CSV to tell if those email addresses are still valid or not, you need to implement your logic and cross-check with some other data sources to determine who should be deleted.